[ In.tpri States Office of Noise
Environmental Protection Abatement and Cental EPA REPORT NO. 550/9-81-101
Agency Wasnmgton 3C 20^60 September 1981
EPA
NOISE IN AMERICA :
The Extent of the Noise Problem
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NOISE IN AMERICA:
The Extent of the Noise Problem
EPA REPORT NO. 550/9-31-101
September 1981
This report has been approved for general availability. The contents of
this report reflect the views of the contractor, who is responsible for the
facts and the accuracy of the data presented herein. This report does not
necessarily reflect The official views or policy of EFA. This report does
not ccnstirute a standard, specification, or regulation.
PERMISSION IS GRANTED TO REPRODUCE THIS MATERIAL WITHOUT FURTHER CLEARANCE
1 (*)
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TABLE OP CONTENTS
Page
1. INTRODUCTION 1
2. CATEGORIES OP NOISE PRODUCERS 2
3. EVALUATING NOISE EXPOSURE AND NOISE IMPACT . . . . U
4. DEVELOPMENT OP ESTIMATES OP THE EXTENT
OP NOISE EXPOSURE 7
5. SUMMARY OP NOISE EXPOSURE ESTIMATES 8
6. EXPOSURE TO MULTIPLE SOURCES 9
REFERENCES 17
APPENDIX A - DESCRIPTION AND MEASUREMENT OP SOUND. . .A-l
APPENDIX 3 - GLOSSARY OF NOISE TERMS B-l
APPENDIX C - TRAFFIC NOISE EXPOSURE IN THE
COMMUNITY C-l
APPENDIX D - AIRCRAFT NOISE EXPOSURE IN THE
COMMUNITY D-l
APPENDIX E - CONSTRUCTION NOISE EXPOSURE
IN THE COMMUNITY E-l
APPENDIX F - RAIL NOISE EXPOSURE IN THE
COMMUNITY F-l
APPENDIX G - INDUSTRIAL NOISE EXPOSURE IN
THE COMMUNITY G-l
APPENDIX H - AGRICULTURAL NOISE EXPOSURE IN
THE COMMUNITY H-l
APPENDIX I - BUILDING MECHANICAL EQUIPMENT NOISE
EXPOSURE IN THE COMMUNITY AND IN
BUILDINGS 1-1
i in)
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TABLE OF CONTENTS (CONTINUED)
Page
APPENDIX J - HOME APPLIANCE, POWER SHOP TOOLS, AND
OUTDOOR POWER EQUIPMENT NOISE EXPOSURE
IN THE COMMUNITY AND IN BUILDINGS, AND
EXPOSURE OF OPERATORS J-l
APPENDIX K - OCCUPATIONAL NOISE EXPOSURE
OF WORKERS K-l
APPENDIX L - TRANSPORTATION NOISE EXPOSURE OF
OPERATORS AND PASSENGERS L-l
' APPENDIX M - RECREATIONAL NOISE EXPOSURE OF
OPERATORS AND PASSENGERS M-l
LIST OF TABLES
1. NOISE SOURCE CATEGORIES INCLUDED IN THIS
REPORT 3
2. SUMMARY OF U.S. POPULATION EXPOSED TO
VARIOUS LEVELS OF Ldn OR HIGHER FROM
NOISE SOURCES IN THE COMMUNITY 10
3. SUMMARY OF U.S. POPULATION EXPOSED TO Ldn
LEVELS OF 45 dB OR HIGHER FROM NOISE SOURCES
INDOORS 11
4. SUMMARY OF U.S. POPULATION EXPOSED TO Leq(2 4)
LEVELS OF 70 dB AND 80 dB OR HIGHER FROM
OCCUPATIONAL AND NON-OCCUPATIONAL NOISE
SOURCES 12
II
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LIST OP TABLES (CONTINUED)
Page
5. U.S. POPULATION EXPOSED TO VARIOUS LEVELS
OF Ldn OR HIGHER FOR COMBINED EXPOSURES
TO TRAFFIC AND OTHER NOISE SOURCES IN THE
COMMUNITY 15
LIST OF FIGURES
1. FACTORS INVOLVED IN ASSESSING NOISE IMPACT . . . . 5
111
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1. INTRODUCTION
How much noise is there in America? Previous EPA documents
(such as the Title IV report [1]*, its several backup techni-
cal documents [2,3,^], and the "Levels Document" [5]) have
addressed this question in varying degrees. In this report
existing information has been used, other information has been
updated, and the range of noise producers has been broadened,
in an attempt to define the extent of the noise problem in
America even more comprehensively.
By virtue of the Noise Control Act of 1972 [6], the EPA was
given a leadership role in assessing and controlling the noise
in this country. Under this authority, EPA has published a
national strategy of noise control [7], which includes goals
for a national program of noise control and various elements
of such a program. The general goal of the national noise
control effort., taken directly from the Noise Control Act, is
"to promote an environment for all Americans free from noise
that jeopardizes their health or welfare." Among the elements
of this national program are the control of major noise
sources (through Federal regulations, State and local control,
labeling, and enforcement activities), study of health and
welfare effects, and dissemination of information to the
public on noise levels and their effects.
A definition of the present extent of the noise problem in
America, in total as well as for individual noise producers,
is crucial in designing a program to control noise sources in
terms of establishing both relative priorities and the amount
of noise control necessary. The purpose of this report, then,
•References are listed on Page 17.
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is to provide information in support of these noise control
activities. Specifically, this report attempts to define the
number of Americans exposed to different levels of noise, and
the sources of noise to which they are exposed.
2. CATEGORIES OF NOISE PRODUCERS
Noise is a ubiquitous by-product of our modern mechanized
society. Since it is difficult to find a device that does not
produce noise, the number of noise producers in this country
is gigantic. To quantify the extent of the noise problem, the
noise producer's are divided in this report into 11 categories,
based primarily on the situations in which the noise producers
occur. Within a given category, therefore, various devices
generally have similar noise-generating properties and opera-
tional characteristics. ¦ •
Table 1 lists the noise categories on which this report con-
centrates (one in each Appendix).
Where does noise affect people? As shown in Table 1, the
categories of noise producers described in this report include
four primary scenarios of exposure in:
The community
Buildings
The workplace
Transportation/recreational devices.
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TABLE 1. NOISE SOURCE CATEGORIES INCLUDED IN THIS REPORT.
See
Category Appendix
Traffic Noise Exposure in the Community C
Aircraft Noise Exposure in the Community D
Construction Noise Exposure in the Community E
Rail Noise Exposure in the Community _ P
Industrial Noise Exposure in the Community G
Agricultural Noise Exposure in the Community H
Building Mechanical Equipment Noise Exposure I
in the Community and in Buildings
Home Appliances, Power Shop Tools, and Garden J
Equipment Noise Exposure in the Community and
in Buildings, and Exposure of Operators
Occupational Noise Exposure K
Transportation Noise Exposure of Operators L
and Passengers
Recreational Noise Exposure of Operators M
and Passengers
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3. EVALUATING NOISE EXPOSURE AND NOISE IMPACT
The extent of the noise produced by a particular device or
source has many dimensions: the intensity, or loudness, of
the noise at a particular point, as described by its "noise
level"] the time characteristics of the noise in terms of its
duration, the time of day it occurs, and whether it is a con-
tinuous or Intermittent sound; the spread of the noise over a
geographic area; and the number of people exposed to the par-
ticular noise. These aspects considered together constitute
the noise exposure. As shown in Pig. 1, the noise exposure
nationwide for a particular noise source, that is, a noise
producer, is based upon:
The emission levels and operating characteristics
of the source
The characteristics of the transmission path between
the source and the people who hear the source noise
The distribution of people relative to the source.
For the purpose of defining noise exposure in Indoor and out-
door environments at specific locations, the SPA has adopted
the yearly day-night sound level, Ldn [5]. Appendix A
describes this measure of noise exposure (and others) In de-
tail. (A glossary of noise descriptors and other acoustic
terms is provided in Appendix B.)
To describe the noise exposure of individuals to levels of
noise that might result in hearing loss, the SPA has adopted
the 24-hour equivalent sound level, L.eq(2U) C5] - This
measure is the equivalent sound level (see Appendix A for a
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Source
Emission
Levels
Noise Level
vs Time
Near Source
Source
Operating
Character istics
Noise Level
vs Time
at Receiver
National
Noise Exposur
(Summed over
all Sources)
Transmission
Path
Characteristics
Population
Distribution
Relative to
Source Location
Assessment
of National
Noise Impact
Noise Criteria
to Protect
Public Health
and Welfare
FIG. 1 . FACTORS INVOLVED IN ASSESSING NOISE IMPACT.
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description/ averaged over a full 2^-hcur day. [When the
r.cise exposure from sources other than workplace noise sources
throughout the day is low enough to result in a negligible
contribution to the 24-hour average, the Lea(2'J) is simply
5 dB higher in level than the 8-hour workplace equivalent
sound level, Leq(8}.]
The pervasiveness of the noise exposure from a particular
noise source is described in terns of the number of people
exposed to various levels of or Leq(24), depending
upon the exposure scenario. The intensity and time character-
istics of the noise and the effects of the transmission path
characteristics are incorporated in the noise measure [either
L,jn or Leq(214)]; the geographic distribution of the
noise source and the people it affects are reflected in the
numbers of people exposed to the various levels. Thus, the
distribution of people as a function of the noise level pro-
vides a very complete description of the extent of noise pro-
blems in America.
However, this description of the noise exposure says nothing
about the effects of the noise on the people exposed. In
order to evaluate such effects to determine if the noise expo-
sure is creating an impact on a certain segment of the. popula-
tion, the noise exposure must be compared with criteria that
have been developed for the various effects, following the
steps shown in Fig. 1.
In the Levels Document [5], E?A has identified an
value of 55 aE outdoors as the level below which the public
health and welfare would be protected with an adequate margin
of safety in residential areas. Similarly, an L
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living space. In order to protect against hearing loss, an
Leq(2*0 of 70 d3 is the level identified (corresponding to
an Leq(8) of 75 dB, when the 8-hour noise exposure
dominates the 2^-hour exposure). "When these identified levels
are exceeded, a noise "impact" is assumed to occur.
In summary, the extent of noise in America is described in
this report as the number of people nationwide exposed to
various noise levels for individual categories of noise
sources. Therefore, evaluating the noise impact with regard
to individual noise effects or for different noise scenarios
involves assessment of the number of people at each level of
exposure above an appropriate criterion level.
DEVELOPMENT OP ESTIMATES OF THE EXTENT OF NOISE EXPOSURE
As described earlier, eleven catecor!;s of noise sources have
been defined for the purpose of estimating the nationwide ex-
tent of noise exposure. Table 1* lists these categories and
the appendices that are devoted to these sources. Each
appendix includes, where appropriate, a description of the
noise model used to develop the exposure estimates, data on
source noise emissions and operating characteristics, trans-
mission path characteristics, population distribution informa-
tion, and the resulting exposure estimates.
Certain noise source categories have been emitted or are in-
complete. They include the noise of commercial establish-
ments, such as automobile repair shops, ar.d the occupational
noise exposure of some industries for which data are lacking.
Similarly, the noise of people and animals has not been in-
cluded (although on the local level, these are often the most
common causes of noise complaints).
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The noise producers covered in this report are mechanical de-
vices. Throughout America, however, an "ambient'' or background
sound level caused by natural phenomena (rain, wind, insects,
etc.) also occurs. .Yost ambient noise levels range from 35-55
dE [3] as reported in surveys. Very little data exist which
can produce estimates of any scientific significance. Ar.bient
noise is believed to have a minimal impact on the population.
The noise exposure estimates contained in this report are based
on the latest information available at present (1980), although
for a number of sources the nonacoustic data used to make the
estimates (number of items in use nationwide, number of people
living in different areas of the country, etc.) are derived
from data from earlier years (typically 1975 and beyond).
5. SUMMARY OP NOISE EXPOSURE ESTIMATES
Appendices C through M provide estimates of the nationwide
noise exposure [in terms of the distribution of population ex-
posed to various levels of L
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To make the noise exposure estimates, existing noise sources
and community data have been used. Generally, the noise source
levels are based upon levels reported in the literature. Ir. a
few cases, however, little data are available for a particular
source. Data on operating characteristics,and population dis-
tributions relative to numbers of sources have been harder to
find, and in these cases, assumptions have been made to produce
the estimates. Wherever possible, the sources of the data are
documented; assumptions used in the analyses are labeled as
such.
As a summary, Table 2 shows the estimated distribution of the
U.S. population as a function of Lcn value for the major
noise categories examined. The L
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TABLE 2. SUMMARY OF U.S. POPULATION EXPOSED TO VARIOUS LEVELS OP Ldn* OR HIGHER FROM
NOISE SOURCES IN HIE COMMUNITY.t
I.(;jn Number (In Millions) of People for Each Noise Category**
(dB) Trafl'1 c Aircraft Constructlontt Rail Industrial
>80
0.1
0.1
—
>75
1.1
0.3
0.1
>70
5.7
1.3
0.6
0.8
>65
19-3
1.7
2.1
2.5
0.3
>60
Jl6.6
11.5
7.7
3-5
1.9
>55
96.8
2'l.3
27.5
6.0
6.9
* L^jn levels are yearly averages, outdoors.
t Note that there Is sane overlay among populations exposed to different noise sources,
I.e., soine of the 96.8 million people exposed to traffic L
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TABLE 3.
SUMMARY OP U.S. POPULATION EXPOSED TO Ldn
LEVELS* OP M5 dB OR HIGHER PROM NOISE SOURCES
INDOORS.
Number (in Millions) oi
People Exposed to L
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TABLE 4.
SUMMARY OP U.S. POPULATION EXPOSED TO Leq(2i»)
LEVELS* OP 70 dB AND 80 dB OR HIGHER FROM OCCUPATIONAL
AND NONOCCUPATIONAL NOISE SOURCES.
Noise Exposure Scenario
Number (in millions) of People
Exposed to Leq(24) Levels at
or above 70 and 80 dB
70 d3
80 d3
0ccupationalt (Appendix K)
Agriculture
Mining
Construction
Manufacturing/Utility
Transportation
Military (D0D)
Total Occupational
Nonoccupational
Transportation Operators/
Passengers (Appendix L)
Aircraft
Motorcycles
Buses
Rapid Transit
Recreational Operators/
Passengers (Appendix
Snowmobiles
Motorcycles (off-road)
Motorboats
Auto Racing
Consumer Products (Appendix
Power Shop Tools
Outdoor Power Equipment
Total Nonoccupational
V ^
• /
J)
NA**
NA
NA
NA
NA
NA
NA
0.4
5-2
10. 4
2.0
1.
2,
2.
0.
30.7
11.0
6" 6"l{ 11
0.3
U. 4
0.5
5-1
1.9
1.0
J7Z
5.2
1.7
2.6
0.1
6.6
rsrzt t
* Leq(24) levels are yearly averages.
t Occupational exposure estimates for Lea(2*0 levels of
7C d5 are unavailable.
**NA denotes not available.
ttThis total may include some people counted twice because of
overlap. A total cf occupational and nonoccupational ex-
posure is not included because of the probability of
additional overlap between the two populations.
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numbers of industrial workers to the use of transportation or
recreational devices. One could, however, for different hypo-
thetical exposure profiles, determine the total exposure of a
person.
With regard to outdoor community exposure, the situation is
somewhat different. Most people are generally subjected to the
noise of more than one of the noise categories. In order to
account for this multiple exposure, it is helpful to note the
manner in which traffic noise, the most dominant noise source,
is distributed throughout the entire population of approximate-
ly 200 million people.* It is not unreasonable to assume that
the exposure of another noise source, like aircraft, might be
distributed across this population in a manner similar to that
of traffic noise. Similarly, construction^, rail, and indus-
trial noise exposure could independently be distributed
throughout this population, in a-manner corresponding to the
traffic distribution. This traffic noise exposure distribution
is as follows (from Table 2):
*This population figure represents the approximate 1980 urban
and rural population, excluding the rural farm population.
TOnly residential construction noise exposure can be distrib-
uted in this manner.
Ldn Ranee (d3)
Number of People Percentage of
(Millions) Total Population
>80
75-80
70-75
65-70
60-65
55-60
<55
103.2
C.l
1.0
i. 6
13.6
27.3
50.2
0.05
0.5
2.3
6.8
13.7
25.1
51.5
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That is, 25'1% of the 2C0 million (non-farm) population in the
United States are exposed to traffic noise levels in the range
of 55 to 60 dB, 13.7S are exposed to traffic noise levels in
the range of 60 to 65 dB, etc.
Accordingly, the 12.8 million people exposed to aircraft levels
of 55 to 60 cB could be similarly distributed so that 25.1%
(3.2 million) are also exposed to traffic levels of 55 to 60
dB, and 13-7% (1.8 million) are also exposed to traffic levels
of 60 to 65 dB, etc. For these people, the combined exposure
will result in a higher total level than either the aircraft or
traffic exposure alone had indicated. In this way, the distri-
bution of people exposed to aircraft and traffic noise, con-
struction and traffic noise, rail and traffic r.oise, and indus-
trial and traffic noise car. be determined.
The distribution of' people who are exposed to traffic but not
aircraft, construction, rail, and industrial noise can then
also be determined. For example, there are ^13-2 million people
with residential exposure greater than 55 dE due to aire raft
(24.3 million), construction (6.0 million, see Appendix E),
rail (6.0 million) and Industrial (6.9 million) noise sources.
Of these, 13-7% or 5.9 million will also be exposed to traffic
r.cise levels of 60 to 65 dB. Since there is a total population
cf 27.3 million exposed to traffic noise levels of 60 to 65 dE,
21.4 million will be exposed to traffic alone in this range.
Then the traffic alone, traffic plus aircraft, traffic plus
construction, traffic plus rail, and traffic plus industrial
distributions can be combined together. The individual and
combined distributions are shown in Table 5.
It is likely that there are some locations (and therefore, some
people) exposed to the noise of more than two sources (e.g.,
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TABLE 5. U.S. POPULATION EXPOSED TO VARIOUS LEVELS OP L^* OR HIGHER
FOR COMBINED EXPOSURES TO TRAFFIC AND OTHER NOISE SOURCES IN THE COMMUNITY.
Ldnt(ciB)
Number (In Millions) of People
Traffic
Only
Traffic
and
Aircraft
Traffic
and
Construction**
Traffic
and
Rail
Traffic
and
Industrial
Total
>80
>75
>70
>65
>60
>58
0.1
0.9
4.5
15.2
36.6
49.2
0.1
0.5
2.2
7.6
16.1
24.3
0.2
0.8
2.8
6.0
0.1
1.0
3.0
6.0
0.2
1.2
3.7
6.9
0.2
1.5
8.1
27.8
63.6
92.4
*I^jn levels are yearly averages, outdoors..
tTYie distribution starts at 58 dB since the analysis Involves combining distributions
of population at 55 dB and above.
**Includes only residential exposure to construction noise.
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traffic, aircraft and rail). However, the distribution of peo-
ple exposed to two non-traffic sources, as .well as to traffic
noise, is unknown and difficult to estimate. Since the total
number of people exposed individually tc construction, rail and
industrial noise above an value of 55 d3 is small 'less
than 7 million each), it is reasonable to expect that the popu-
lation distribution for various L
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REFERENCES
1. Administrator of the EFA, "Report to the President and
Congress on Noise," in compliance with Title IV of Public
Law 91-604, the Clean Air Act Amendments of 1970, Senate
Document 92-63, U.S. Government Printing Office, February
1972.
2. EPA Technical Information Document NTID300.1, "Noise
from Construction Equipment and Operations, Euilding
Equipment and Home Appliances," (EPA Contract 66-04-0047,
Bolt Beranek and Newman Inc.).
3. EPA Technical Information Document NTID300.3, "Community
Noise," (EPA Contrary 63-04.-0046, Wyle Laboratories) .
4. EPA Technical Information Document NTID300.13, "Trans-
portation Noise and Noise from Equipment Powered by In-
ternal Combustion Engines," (EPA Contract 68-04-0046, Wyle
Laboratories).
5. Environmental Protection Agency, "Information on Levels
of Environmental Noise Requisite to Protect Health and
Welfare with an Adequate Margin of Safety," EPA Report No.
500/9-74-004, March 1974.
6. The Noise Control Act of 1972, PL 92-574.
7- Environmental Protection Agency, "Toward a National
Strategy for Noise Control," April 1977-
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APPENDIX A. DESCRIPTION AND MEASUREMENT OP SOUND
The nature of sound Is often debated with the following ques-
tion: if a tree falls in the forest, and no one is near to
hear it fall, Is there a sound? In other words, does sound
deal with a cause (a vibrating object such as the falling tree)
or with an effect (the sensory experience of hearing)? The
answer is that sound is both these things. It is both a physi-
cal event and a physiological sensation.
The sensation of sound Is a result of oscillations in pressure,
particle displacement, and particle velocity, in an elastic
medium between the sound source and the ear. Sound is caused
when an object is set into vibration by a force. This vibra-
tion causes molecular movement of the medium in which the
object is situated, thereby propagating a sound wave. Sound is
heard when a sound wave impinges on the human ear and is recog-
nized by the brain. Further, the characteristics of the sound
wave must fall within the limitations of the human ear for the
sound to be heard because the human ear cannot hear all sounds.
Sound frequencies (pressure variation rates) can be too high
(ultrasonic) or too low (infrasonic), or the sound amplitudes
may be too soft to be heard by humans.
A.l Sound Propagation
Sound Is transmitted from the sound source to the air by the
movement cf molecules in the medium. This molecular movement
is called a sound wave.
A-i
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In air, sound waves are described in terms of propagated
changes in pressure that alternate above and below atmospheric
pressure. These pressure changes are produced when a vibrating
sound source actually "bumps" into the adjacent air molecules
forcing them to move. These molecules, in turn, bump into
others farther away from the source, and so on. Thus, the
energy from the sound source is imparted to the air molecules
and thereby is transmitted through the medium. An analagous
situation occurs when dropping a pebble into a still pond.
When the pebble hits the water, waves on the surface emanate
from the point of impact in all directions, moving outward in
concentric spheres, while individual water molecules merely
oscillate up and down in one place.
There are two phases to a sound wave: compression and rarefac-
tion. The compression phase occurs when the air molecules are
forced close together (causing an instantaneous increase in air
pressure), and the rarefaction phase occurs when the air mole-
cules are pulled apart from each other (causing an instanta-
neous decrease in atmospheric pressure). The complete sequence
of one compression and one rarefaction is called a cycle. The
cycle of a sound wave and its component parts are illustrated
in Fig. A.l.
A.2 Perception of Sound
The human ability to perceive a specific sound depends upon
its magnitude and character, as differentiated from the magni-
tude and character of all the other sounds in the environment.
A-2
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0)
\
VP
Press
ure
~
(")
Compression
(Increase in Pressure)
Rarefaction
(Decrease in Pressure)
k
One Cycle
Average
Atmospheric
Pressure
FIG. A . 1 . CYCLE OF A SOUND WAVE AND ITS COMPONENT PARTS
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A number of qualitative descriptions may be used to describe a
sound, such as:
Magnitude - loud or faint
Broadband frequency content - high-pitched hiss or low
rumble
Discrete frequency content - tonal or broadband
Intermixing of pure tones - harsh or melodic
Time variation - intermittent, fluctuating
steady or impulsive
Duration - long or short.
Conventional measures of sound attempt to determine its magni-
tude with respect to human perception, trying to account for
the frequency response characteristics of the ear. Most mea-
sures do not account for other subjective attributes. Such
attributes are difficult to measure individually, anc it is
even more difficult to combine them into a single measure.
However, one or more of these at-tributes may be important ir.
enabling a human to perceive a specific sound, for example, an
Intermittent impulsive "rat-tat-tat" is more easily distin-
guishable than a steady broadband sound. To account for these
attributes, which are not easily measured, some noise rating
scales have fixed penalties that are applied to the measured
level to increase its value.
A.3 Magnitude of Sound
The unit used to measure the magnitude of sound level is the
decibel. In the phrase, "The sound level is so many decibels''
its use Is analogous to the use of "inch" in the phrase, "The
length is so many inches" or to "degree" in the phrase, "The
A-4
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temperature on the Celsius scale is so many degrees". However,
unlike the scales of length and temperature, which are linear
scales, the sound level scale is logarithmic. For measurement
of sound pressure, sound pressure level (SPL) is defined as 10
times the logarithm to the base 10 of the ratio of the measured
mean square sound pressure (P) to the square of a specified
reference sound pressure (Pr):
SPL = 10 log (P/Pr)2,d3. (A.1)
By definition, therefore, a sound that has 10 times the energy
of the reference sound is 10 decibels (dB) greater, and one
that has 100 times the energy (or 10 x 10 times) of the refer-
ence sound is 20 dB greater (10 + 10 dB).
The ear is sensitive to a wide range of sound levels, and this
creates many difficulties in working with absolute sound pres-
sure units. For instance, the human ear is sensitive to a
pressure range greater than 0.00002 to 20,000 newtons per sq
meter. Because of the awkwardness and difficulty of working
with such a broad range of absolute units, the decibel has been
adopted to compress this large range and more closely follow
the response of the human ear.
The use of the logarithmic decibel scale requires somewhat dif-
ferent arithmetic than we are accustomed to using with linear
scales. For example, consider two similar but independent
noise sources operating simultaneously, and each producing an
average sound pressure P. The sound energy (square of the
sound pressure) generated by the two sources will add together
to give sound energy twice that which would result from either
source operating alone.
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However, the resulting sound pressure level (SPL') in dB from
the combined sources will be only 3 dB higher than the level
produced by either source alone, since the logarithm of 2 is
0-3 and 10 times 0.3 is 3- This solution can be shown mathe-
matically as follows:
SPL' = 10 log (P + P ) / Pr = 10 log 2 P /Pr
= 10 log 2+10 log P /Pr = 3 + SPL. (A.2}
If we have two sounds of different magnitude from independent
sources, then the level of the sum will always be less than 3
dB above the level produced by the greater source alone. If
the two sound sources produce individual levels that are dif-
ferent by 10 dB or more, then adding the two together produces
a level that is not significantly-different from that produced
by the greater source operating alone, as illustrated in Fig.
A . 2.
Two sounds that have the same sound pressure level may "sound"
quite different (i.e., a rumble vs a hiss) because of differing
distributions of sound energy in the audible frequency range.
The distribution of sound energy as a function of frequency is
termed the "frequency spectrum" (see Fig. A.3 for an example).
The spectrum is important to the measurement of the magnitude
of sounds because the human ear is more sensitive to sounds at
seme frequencies than at others. For example, the human ear
hears better in the frequency range of 1,000 to 10,000 cycles
per second (or Hertz) than at very much lower or higher fre-
quencies. Therefore, in order to determine the magnitude of a
sound on a scale that is proportional to the magnitude as per-
ceived by a human, it is necessary to weight that part of
A-6
-------
2
P P dB
Combination
of Sounds
Not. I and 2
Combination
of Sounds
Not. 1 and 2
Sound No.2
Sound No. I
Sound No.l
m m—f
// Sound No.2 //.
ul
Pressure Pressure Decibels (a) Adding Two Sounds of Equal (b) Adding Two Sounds of Very
Scale Squared Scale Magnitude Different Magnitude
Scale
A.2. EXAMPLE OF THE CHANGE ON THE DECIBEL SCALE RESULTING
FROM ADDING THE ENERGIES OF TWO SOUNDS TOGETHER,
-------
Frequency spectrum of
the sound (a different
level exists at each
part of the spectrum)
C
9
O
wi
1
&
•
>
a
o
o
The acoustic energy
across the spectrum
odds to give the
overall sound pressure
level (a single number)'
_1L
31.5 63 125 250 500 1,000 2.000 4,000 8.000
Octav* Band Cenfer Frequency in C/clas par Second (Hz)
Piano
Scale
261.6
(Middle C)
1046.4
(2 Octaves
above Midd.e C)
FIG. A.3. EXAMPLE OF A FREQUENCY SPECTRUM OF
A SOUND,
.H-
-------
the sound energy spectrum hunans hear most easily; that is,
count it more heavily when adding up the total sound energy as
perceived. Figure A. 4 illustrates this concept of weighting
the physical sound energy spectrum to account for the frequency
response of the ear.
A.4 Frequency Weighting
Scientists who work in acoustics have attempted for many years
to find the ideal method to weight the frequency spectrum of
sound to match accurately the perception of sound by the human
ear. These attempts have produced many different scales of
sound measurement, including A-welghted sound level (and also
B, C, D, and E-welghted sound levels), perceived noise level,
and loudness. A-weightlng, which was developed In the 1930s
for use in a s~und level meter, .accomplishes the weighting by
an electrical r.etwork that works in manner similar to the bass
ana treble controls on a hi-fi set.
A-weightlng has been used extensively throughout the world to
measure the magnitudes of sounds of all types. Because of its
universality, it was adopted by the EPA and other government
agencies for the description of sounds in the environment. A
newer weighting, such as D or E, based on the decade of re-
search leading to the perceived noise level scale, might even-
tually supplant A-welghting as the universal method. But until
one of these newer scales is in common use ana its superiority
over A-weightlng for measurement of environmental sounds is
demonstrated, A-weighting Is expected to dominate.
The zero value on the A-welghted sound level scale (sound
level, for short) is the reference pressure of 20 micronewtons
A-9
-------
y
Mund SfMKfrum
y/
VAW
V /.
7//\
Aital«**r><«
w
Hcvnnq
• 1 *
Sptciium
W«ngrt«»d to*
N«i«in+u
50 100 $00 l.000 S OOS 13.000 JD.OX
fiwtjytr.tr «n t /Ha s«r uicend
FIG. A,4. WEIGHTING THE MEASURED SPECTRUM TO
ACCOUNT FOR THE FREQUENCY RESPONSE
TO THE HUMAN EAR.
1 O
mIm sj
-------
per square meter (uN/M^). This value was selected because it
approximates the smallest sound pressure that can be detected
by a human. The average A-weighted sound level of a whisper at
a 1-meter distance from the person who is whispering is 40 dB;
the sound level of a normal voice speaking 1 meter away is 57
dB, a shout, 1 meter away, is B5 dB.
A.5 Time Variation of Sound
Generally, the magnitude of sound in the environment varies in
a random fashion with time. There are many exceptionsj for ex-
ample, the sound level of a waterfall is relatively constant
with time, and the sound level of a room air conditioner is
periodically high and low, depending on whether it is on or
off. But in most places the outdoor sound is ever-changing in
magnitude, because it is influenced by sounds from many
sources—people, animals, many types of vehicles, near and
far. Figure A.5 illustrates how the sound level of different
types of sounds vary over time.
In one sense, the variation of sound levels with time is analo-
gous to the variation in shade (light to dark) in a picture or
one's surroundings. Similarly, the changing characteristics of
the subjective attributes ana frequency spectrum to the ear
might be analogous to change in color to the eye. It may be
that the changes in magnitude and character of the sound in the
environment with time add richness to the human environmental
experience, as do visual changes in intensity and color. Cer-
tainly the varying sounds of bird songs and rustling leaves in
the forest are more rewarding than the utter silence that pre-
cedes a storm or the steady hum of a noisy ballast transformer
in a fluorescent light. Changing patterns of sound serve to
A-ll
-------
Sound
Leve I
Constant Sound -
Waterfall
-~Time
Sound
Level
Periodic Sound -
Air Conditioner
^Tirne
Sound
Level
Random Sound -
Neighborhood
ime
FIG. A.5. EXAMPLES CF SOUND LEVEL VARIATION OVER TIME
-------
make us continually aware of life going on around us and seem
to provide assurance that all is well. However, if the fluctu-
ation in magnitude of sound exceeds the range that is acceptable
in a specific context, if th'e average sound level is high enough
to Interfere with verbal communication, Job performance, or some
other activity, or if a sound of unusual character or undesir-
able connotation is heard, the subconscious feeling of well-
being may be replaced with feelings of adversiveness and annoy-
ance.
It is easy to measure the continuously changing magnitude of the
sound level. It may be displayed on a graphic level recorder,
in which a pen traces a line on a sheet of moving paper. Fig.
A.6 Illustrates two 8-min. samples of such a recording. Several
features of these two samples should be noted.
The first feature is that the sound level varies with time over
a range of 33 dB, which is a ratio of 2000 to 1 in sound energy.
Second, in these two samples, the sound appears to be charac-
terized by a fairly steady-state lower level, upon which the
increased sound levels associated with discrete (individual)
single events are superimposed. This fairly constant lower
level is often called the residual sound level. An example of
residual sound is the continuous sound one hears in the backyard
at night, when no single source can be Identified, so the sound
seems to come from "all around." The distinct sounds that are
superimposed on the residual sound level, such as the aircraft
overflight, cars, and dogs barking, can be classified as the
result of a succession of single events.
A-13
-------
Enrly Afternoon
CN
z
a
o
CN
CO
"a
.0)
>
a>
•a
c
3
0
UO
"O
_C
O)
-------
Each single event may be partially characterized by its maximum
level. It may also be characterized by its time pattern. The
sound level of the aircraft in the example is above that of the
residual sound level for approximately 80 sec, whereas the
sound levels from the cars passing by on the street are above
the residual sound level for much shorter durations, ranging
between about 5 and 20 sec. Clearly, if the sound associated
with these single events were of sufficient magnitude to in-
trude on an Individual's activities—conversation, thinking,
watching television, etc.—the duration factor might be ex-
pected to affect his degree of annoyance. Similarly, it might
be anticipated that the number of times such an event recurred
also would affect his degree of annoyance.
The data from these continuous recordings of sound are very
instructive in providing an understanding of the nature of the
outdoor sound environment at any neighborhood location. How-
ever, in order to quantify an outdoor sound environment at one
location so that it can be compared with the sound environment
at other locations, it Is useful to simplify its description by
eliminating much of the temporal detail. One way of accom-
plishing this simplification is to measure the value of the
residual sound level and the values of the maximum sound level
for specific single event sounds at various times during the
day, using either a simple sound level meter or the continuous
graphic level recording of its output. Another method of quan-
tifying the sound environment is to determine the statistical
properties of the sound level by attaching a statistical anal-
yzer to the output of the sound level meter. This procedure
allows one to determine the amount of time that the sound level
exceeds any stated sound level, or, conversely, the sound level
that is exceeded for a stated percentage of the time. A third
A-15
-------
method is to determine the value of a steady-state sound that
has'the same A-welghted sound energy as that contained in the
time-varying sound. This value is termed the equivalent sound
level. These three methods of deriving single number measures
of time-varying noise levels are illustrated in Fig. A. 7.
Each of these descriptors has its own special usefulness.
Residual and maximum sound levels are easily measured by simple
equipment; however, such measurements give no indication of the
duration of the various single events, nor a notion of the
average "state" of the environment.
The statistical method is relatively difficult to accomplish
with simple equipment. Most monitoring systems designed for
the purpose can give the complete detailed statistical distri-
bution curve of sound level vs time for any desired duration:
for example, each hour of the day, daytime or nighttime, or a
24-hour day. Such a curve is often a most useful reduction of
the detail contained in the graphic level recording, although
it eliminates all information about specific events.
The equivalent sound level is also best measured with an in-
strument or monitoring system designed specifically for this
purpose. A single value can be obtained for any desired dura-
tion, a value that Includes all of the time-varying sound ener-
gy in the measurement period. As such, it is a more complete
description than a single value of level and time taken from a
statistical description. For example, if the "level that is
exceeded 10% of the total time" is used as the descriptor of
the time-varying sound, its value remains constant and
independent of the magnitudes of all higher level sounds as
long as their durations are less than 10% of the total time,
A-16
-------
(a) Maximum Level and Number of Events
_N=J 2 3 4_ L
max
residual
(b) Statistical Levels
L = Level Exceeded x Percent of the Time
x
(c) Equivalent Level
eq
Lg^ = Energy Equivalent Level
FIG. A.7. THREE MEASURES OF ENVIRONMENTAL NOISE.
-------
whereas the energies associated with these sounds of hlgner
level are fully accounted for in the equivalent sound level.
The major virtue of the equivalent sound level is that its mag-
nitude correlates well with the effects on humans that result
from a wide variation in types of environmental sound levels
and time patterns. It has been shown to provide good correla-
tion between noise and speech interference and noise and risk
of hearing loss. It also is the basis for the measure of the
total outdoor noise environment, the day-night sound level,
which correlates well with community reaction to noise and to
the results of social surveys of annoyance to aircraft noise.
The day-night sound level is defined as the A-weighted equiva-
lent sound level for a 2^-hour period with a +10-dB weighting
applied to the equivalent sound -levels measured during the
nighttime hours of 10 p.m. to 7 a.m. The nighttime weighting
increases the levels measured during the nighttime by 10 dB.
Hence, an environment that has a measured daytime equivalent
sound level of 60 dB and a measured nighttime equivalent sound
level of 50 dB has a weighted nighttime sound level of 60 dB
(50 + 10) and a day-night sound level of 60 dB. Examples of
measured day-night sound levels are given in Pig. A.8.
A.6 Characterizing Specific Sounds
The sounds that, combined, make environmental sound can be con-
sidered a collection of steady-state sources (such as trans-
formers) and the sounds of time-varying single-event sources
which occur at random or regular intervals (such as moving .
vehicles), superimposed on a quasisteady-state residual or
background level of sounds which are indistinguishable.
-------
qualitative
DESCRIPTIONS
DAY - NIGHT
SOUND LEVEL
DECIBELS
(dB re 20^N/m2)
- 90-
-80-
ClTY NOISE
(DOWNTOV/N MAJOR +¦
METROPOLIS )
NOISY UR3AN
VERY NOISY
URBAN
SUBURBAN
-70-
MALL TOWN & ....
OUIET -50^
SUBURBAN
— 40—
OUTDOOR LOCATIONS
LOS ANGELES—3rd FLOOR APARTMENT NEXT TO
FfiEEWAY
LOS ANGELES - 3/4 MILE FROM TOUCH DOWN AT
MAJOR AIRPORT
LOS ANGELES- DOWNTOWN WITH SOME CON'
STRUCT10N ACTIVITY
HARLEM- 2nd FLOOR APARTMENT
BOSTON-ROW HOUSING ON MAJOR AVENUE
WATTS - 0 MILES FRO.y TOUCH DOWN
AT MAJOR AIRPORT
NEWPORT- 3.5 WILES FROM TAKEOFF AT
SMALL AIRPORT
LOS ANGELES- OLD RESIDENTIAL AREA
FILLMORE-SMALL TOWN CUL- dff-SAC
SAN DIEGO - WOODED RESIDENTIAL
CALIFORNIA - TOMATO FIELD ON FAR.Si
FIG. A.8. EXAMPLES OF OUTDOOR DAY/NIGHT SOUND LEVELS IN
dB MEASURED AT VARI0U5 LOCATIONS.
A-1S
-------
The descriptor of the steady-state sound Is simply the A-
weighted sound level and the duration of the event. Hie des-
criptor for the time-varying sounds associated with single
events must include both magnitude and duration. One method is
to measure the maximum sound level and the duration in which
the sound level Is above a stated number of decibels below the
maximum level: for example, the number of seconds between the
time that the sound rises from 10 dB below maximum, to maximum,
and falls again to 10 d3 below maximum. An alternative des-
cription, which produces a single value for the sound of the
single event is the sound exposure level, the level of the
total sound energy at the microphone resulting from the event.
These concepts are illustrated in Pig. A.9.
A.7 Summary of Key Descriptors of Sound
For the purpose of quantifying environmental sound in this dis-
cussion, four quantities listed in Table A.l are useful. All
are based on the A-welghting, which accounts approximately for
the frequency response of the ear. All have logarithmic
scales, all use the decibel (d3) as their unit, and all have
the same magnitude of the reference sound pressure of 20 micro-
newtons per square meter.
A-20
-------
m
T3
>
0)
"O
c
D
0
ui
-o
£
1
<*
Maximum Sound Level
Shaded Area in Which
Energy is Summed to
Obtain Total Energy
for the Event - Sound
Exposure Level
10 dB
Residual Level
T ime
FIG . A . 9 .
DESCRIPTION OF THE SOUND OF A SINGLE EVENT
A- 21
-------
TABLE A.l. PRINCIPAL DESCRIPTORS OP ENVIRONMENTAL SOUND.
Quantity
Symbol
Abbreviation
Short
Description
Principal
Uses
Sound
Level
Sound
Exposure
Leve 1
Equivalent
Sound
Level
eq
Day-Night Lr=r,
Sound
Level
Mean square value of
A-welghted sound pres-
sure level at any time
referenced to a refer-
ence pressure
Time integral of the
mean square A-weight-
ed sound pressure
referenced to a mean
square reference pres-
sure and 1-sec dura-
tion
Level of a steady
sound that has the
same sound exposure
level as a time-
varying sound over
stated tine inter-
val
Equivalent sound
level for a 2U-hr
period with a +10
dB weighting applied
to all sounds occur-
ring between 10 p.m.
ana 7 a.m.
Describes magni-
tude of a sound
at a specific
position and
time
Describes mag-
nitude of all of
the sound at a
specific posi-
tion accumulated
during a speci-
fic event, or
for a stated
time interval
Describes aver-
age (energy)
state of environ-
ment; usually em-
ployed for dur-
ations of 1 hr
[LeqCl)], b hr
•iLeq(b)], or 2^
hr CLeqC24)I
Describes average
environment in
residential situ-
ations; account-
ing for effect cf
nighttime noises;
often is averaged
over a 365-day
year
A-22
-------
APPENDIX B. GLOSSARY OP HOISE TERMS*
Acoustic Intensity - see Sound Intensity.
Acoustic Power - see Sound Power.
Ambient Noise - Ambient noise is the overall composite of
sound in a given environment.
Amplitude - A sound's amplitude can describe the magnitude of
sound at a given location away from the source, that is,
its sound pressure or sound intensity, or it can refer to
the overall ability of the source to emit sound measured
by its sound power.
Anechoic Room - An anechoic room has essentially no boundaries
to reflect sound energy generated therein. Thus, a sound
field generated within an anechoic room is referred to as
a free field.
Audiogram - An audiogram is a record of hearing threshold lev-
els as a function of frequency. The threshold levels are
referenced to statistically normal hearing threshold
levels.
Audiometer - An audiometer is an instrument for measuring
hearing sensitivity.
Critical Eand - A critical band is a frequency bandwidth char-
acteristic of human ears. Noise at frequencies outside
this bandwidth has minimal effect cn masking a tone at
any given critical band's center frequency.
Cycle - A cycle of a periodic function is the complete se-
quence of values that occur in a period.
Cycle per second - see Frequency.
Decibel (dB) - The decibel is a convenient means for
describing the logarithmic level of sound intensity,
sound power, or sound pressure above arbitrarily chosen
reference values.
*This glossary has been adapted from the SPA Report "Noise
Training Manual," by P.L. Michael et al, December 1977-
3-1
-------
Diffuse Sound Field - A diffuse sound field has sound pressure
levels that are essentially the same throughout, and the
directions of propagation are wholly random in distribu-
tion.
Effective Sound Pressure - The effective sound pressure at a
given location is found by calculating the root-mean
square value of the instantaneous sound pressure measured
over a period of time at that location.
Free field - In a free field, sound that Is radiating from a
source can be measured accurately without interference
from the test space. Absolute free-field conditions are
rarely found, except In expensive anechoic (echo-free)
test chambers; however, approximate free-field conditions
exist in any homogeneous space where the distance from
reflecting surfaces to the measuring location is much
greater than the wave lengths of the sound that is being
measured.
Frequency - The frequency of sound describes the rate at which
complete cycles of pressure are produced by the sound
source. The unit of frequency is the cycle per second
(cps) or preferably, the hertz (Hz). The frequency range
of the human ear is highly dependent upon the individual
and the sound level, but a person with normal hearing
will have a frequency range of approximately 20 to 20,GOO
Hz at moderate sound levels. The frequency of a sound
wave that is heard by a listener is the same as the
frequency of the vibrating source if the distance between
the source and the listener remains constant; however,
the frequency detected by a listener Increases or
decreases as the distance from the source decreases or
increases (Doppler effect).
3-2
-------
Hertz - see Frequency.
Infransonlc Frequency - Sounds of an lnfrasonic frequency are
below the audible frequency range.
Intensity - see Sound Intensity.
Level - The level of any quantity, when described lr. decibels,
Is 10 times the logarithm of the ratio of that quantity
to a reference value.
Loudness - The loudness of sound 1s an observer's impression
of Its amplitude, which includes the response character-
istics of the ear.
Noise - The terms "noise" and "sound" are often used inter-
changeably but, generally, sound Is descriptive of useful
communication or pleasant sounds, such as music; whereas,
noise Is used to describe dissonance or unwanted sound.
Noise Reduction Coefficient (NRC) - The noise reduction coef-
ficient is the arithmetical average of "he sound absorp-
tion coefficients of a material at 250. 500, 1000, and
2C00 Ha.
Octave Band - An octave band is a frequency bandwidth that has
an upper banc-edge frequency equal to twice its lower
band-edge frequency.
One-Third Octave Band - A frequency band whose cutoff fre-
quencies have a ratio of 2 1/3, which is approximately
1.26. The cutoff frequencies of 891 Hz and 1123 Hz
define a one-third octave band :en:erec at 1000 Hz.
Peak Level - The peak sound pressure level is the maximum in-
stantaneous level that occurs over any specified time
period.
Period - The period (T) is the time (in seconds) required for
one cycle of pressure change so take place; hence, *,z is
the reciprocal of the frequency.
B-3
-------
Pitch - Pitch is a subjective measure of auditory sensation
that relates primarily to the frequency of a sound.
Power - see Sound Power.
Pure Tone - A pure tone is a sound wave whose instantaneous
sound pressure is a simple sinusoidal function of time.
Random-Incidence Sound Field -see Diffuse Sound Field.
Random Noise - Random noise is made up of many frequency com-
ponents whose instantaneous amplitudes occur randomly as
a function of time.
Reverberation - Reverberation occurs when sound persists after
direct reception of the sound has stopped. The rever-
beration of a space is specified by the "reverberation
time," which is the time required, after the source has
stopped radiating sound, for the rms sound pressure to
decrease 60 d3 from its steady-state level.
Root-Mean Square Sound Pressure - The rcot-mean-square (rms)
value of a changing quantity, such as sound pressure, is
the square root of the mean of the squares of the instan-
taneous values of the quantity.
Sound - see Noise.
Sound Intensity (I) - The sound intensity at a specific
location is the average rate at which sound energy is
transmitted through a unit area normal to the direction
of sound propagation. The units used for sound intensity
are joules per square meter per second. Sound intensity
is also expressed in terns of a level (sound intensity
— IP
level, Li) in decibels referenced to 10 ~~ watts per
square meter.
Sound Power (P) - The sound power of a source is the total
sound energy radiated by the source per unit time, Sound
power is normally expressed in terms af a level (sound
power level, ^D) in decibels referenced to 13
watts.
3-ii
-------
Sound Pressure (p) - Sound pressure normally refers to the rms
value of the pressure changes above and below atmospheric
pressure when used to measure steady-state noise. Short-
term or impulse-type noises are described "by peak
pressure values. The unit used to describe sound
pressures is the pascal (Pa); 1 Pa equals 1 newton per
square meter (N/m^). Sound pressure is also described
in terms of a level (sound pressure level, Lp) in
decibels reference to 10~5 Pa.
Standing Waves - Standing waves are periodic waves that have a
fixed distrbution in the propagation medium.
Transmission Loss (TL) - Transmission loss of a sound barrier
may be defined as 10 times the logarithm (to the base 10)
of the ratio of the incident acoustic energy to the
acoustic energy transmitted through the barrier.
Ultrasonic - The frequency of ultrasonic sound is higher than
that of audible sound.
Velocity - The speed at which the regions of sound-producing
pressure changes move away from the sound source is call-
ed the velocity of propagation. Sound velocity (c)
varies directly with the square root of the density ana
inversely with the compressibility of the transmitting
medium as well as with other factors; however, in a given
medium, the velocity of sound is usually considered
constant under normal conditions. For example, the
velocity of sound is approximately 3^ m/sec (1,130
ft/sec) in air, 1^32 m/sec (4,7U0 ft/sec) in water, 3362
m/sec (13,000 ft/sec) in wood and 5029 m/sec (lc,500
ft/sec) in steel.
Wavelength - The distance required to complete one pressure
cycle is called one wavelength. It may be calculated
from known values of frequency (f) and velocity (c):.\ =
c/f.
-------
White Noise - White noise has an essentially random spectrum
with equal energy per unit frequency bandwidth over a
specified frequency band.
B-6
-------
APPENDIX C. TRAFFIC NOISE EXPOSURE IN THE COMMUNITY
C.l Urban Traffic Noise Exposure
C.l.l Noise exposure model
Estimates of the noise exposure caused by roadway, traffic in
urban areas nationwide have been generated by the EPA using
the National Roadway Traffic Noise Exposure Model (NRTNEM)
[C-l]. This computer model simulates the noise generated by
traffic flow on the several categories of roads throughout the
country, and estimates noise exposure by. considering the dis-
tribution of the population relative to the roadway network
and the characteristics of vehicles operating on that network.
The baseline year for which detailed information on roadway
traffic conditions, vehicle operational characteristics, and
population distributions are Input in the computer program is
197^. (The model makes estimates of noise exposure for later
years by internally projecting these characteristics as neces-
sary. For this report, the estimates obtained for 1980 are
used.)
The model contains six functional classifications of roadways,
with traffic flow characteristics broken down by place and
size. Table C.l lists the mileage, average daily traffic
(ADT), anc daily vehicle miles traveled (DVMT) in 197U for
each of the roadway classifications used in the model. The
roadway mileage does not change from 197^ to 1980, but the ADT
and DVMT are internally increased in the model by factors that
reflect projections for the current number of vehicles or. the
road. These factors are a complex function of the different
traffic mix ir. each place size/ roadway type category. Al-
though the average overall vehicle growth factor between 197^
and 1980 is not calculated by the model, based on the increase
in ADT and DV>:T, it is estimated as approximately 20%.
-------
TABLE C.l. 1974 DISOTUBUTION OP HIL£AQK, AOT, AND WW [C-l].
ItOADWAV 'IVPE
Place*
Size
Parameter
Interstate
Other Freeway
& Expreuuway
Major
Arterlala
Minor
Arterlala
Collectors
Local
>m
Ml lea
Aur
iwwr
1.990
71,066
11)9,582,260
1.719
66.170
116.256.030
9.861
10,768
105,071,210
11,103
9.315
131.369.115
12.851
3.703
18,626.682
81,217
1.129
95.111,863
1M
to
2M
Ml lea
ADT
uvwr
1.069
60,228
112,566,132
1.527
32.510
19.700.796
5.156
17.397
09.690.932
10.219
6.098
70,190.662
10,300
3,196
36,036,760
61,678
656
12,128,768
500k
to
1M
Ml lea
Ai;r
DVMT
1.1/7
16,997
69.111,569
739
31.036
25.152.60il
1.031
16.359
65.992.206
6.320
8,015
50,811.100
7,190
3,760
27,031.100
17.166
672
31.897.152
200k
to
'jOOk
Ml leu
AW
LVMT
1,713
10.367
70,359.601
1.076
20.012
31.001.712
5,566
16,029
09.217,111
8.569
8,1/0
75,579.130
7,897
3,812
30,103,361
58,252
839
10,873.128
100k
to
200k
Ml lea
Ai/r
iwr
051
32.190
27.190.260
803
22.901
18.156.152
3.051
11.901
57,352.913
5.502
7,301
10,170,102
5,711
3,287
18.781.918
36,697
619
23.816,353
50k
to
look
Ml lea
AW
IWMT
512
21.913
11.219.156
600
19,9/1
11.902.600
3.335
12.376
11.2/3.960
1.115
6.057
26,923.365
1,531
2.917
13.225.678
29.281
615
18,888,180
j
i
Ml lea
AW
DVMT
397
23.251
9.230.61/
11/
16.0/5
/,513,125
1,202
11.301
• 18.716.290
5.377
5.130
29.197.110
5.828
2,181
11,176,752
33,151
631
a.109.179
5k
to
2'jk
Miles
Aur
DVMT
099
10,206
16.367.111
1.099
13.211
13.313.016
9.652
0.922
06.115.111
12.121
1,255
51,587.620
13,130
1,916
25.550,980
75.131
195
37.338.315
ftjral
Ml leu
AW
DVMT
31.711
13.700
131.092.800
05.716
1.623
396,265,060
155,517
2.523
392.115.081
135,517
899
307,171.613
307.917
370
U3.929.290
1.912.733
98
190,387.831
NOlli: Al/T - L)VMT/MIL£S IS *111E DfcHIVfcD QUAMl'm
•Place Size In number ol' people (k = thousand, M •» million).
-------
Table C.l includes data also for rural areas. These data are
used In Sec. C.2 for rural noise exposure estimates.
In order to estimate the noise levels generated on this road-
way network, the model uses four major categories of vehicles
(light vehicles, trucks, buses, and motorcycles), which are
further divided into 14 subcategories. For each of these sub-
categories, the model contains four operational modes: idle,
acceleration, deceleration, and cruise. Data on the emission
levels appropriate to each operating mode for each vehicle and
the percentage of time that a vehicle is operated in a par-
ticular operating mode are included in the model. For each
category of roadway, the model also contains data on the rela-
tive mix of vehicles.
The national urban population in 19^0 is estimated in the
model to be 160 million people.* It is divided among eight
place sizes, with four population density categories for each
place size. Table C.2 lists the population and areas associ-
ated with each of these categories (as well as for rural).
The noise level at a given distance from a particular roadway
is determined by summation cf the noise levels of the indi-
vidual vehicles on that roadway. Depending upon the popula-
tion density, one of three propagation curves is used to esti-
mate the noise level at various distances away from the road-
way. Using data on the distribution of traffic over 2'4- hour
periods, the Lcjns at different distances from the roadways
are determined.
*1970 Series I projections.
C-3
-------
TABLE C.2. 1980 POPULATION (IN MILLIONS) AND LAND AREA (IN SQUARE MILES) BY PLACE SIZE AND POPULATION
DhNSm CLASS [C-l].
Population
Density
Category Parameter
Place Size
1M 500k 200k 100k 50k 25k 5k Urban
>2M -2M -1M -500k -200k -100k -50k -25k Ibtal
Rural
1 Population 6.06 2.25 0.39 1-64 1.18 1.09 0.48 I.89
Area 134.2 272 63 215 217 329 58 220
14.98 71.88
1570.2 3,476,938
Population 24.06 4.37 2.18 10.64 2.99 2.16 3.04
Area 35/6 775 488 4558 1305 1115 896
5.07 ' 54.51 0
1261 13,970.0 0
Population 23.32 11.91 8.99 6.88 6.98 4.62 3-58
Area 8358 5080 4426 5790 5266 4195 2230
8.63 74.91 0
4527 39,872.0 0
Population 0 5-72 5.67 0
Area 4U89 4584 0 0
0
0
0 1.96 2.75 16.10 0
0 2769 5829 17,262.0 0
'ibtal Population 53.44 24.25 17.22 19-16 11.15 7.86 9.06 18.34 160.48 71.88
Area 12,064.2 10,2l6.0 9561.0 10,563.0 6850.0 5639-0 5953-0 11,828.0 72,674.2 3,4/6,938
Total Population = 232.36 million
Total I.and Area = 3,549,612.2 sq mllea
-------
The model also considers both primary and secondary exposure,
that Is, the primary exposure of a person to the noise of a
roadway adjacent to his residence, and the secondary exposure
to the variety of roadways In the nearby vicinity of his resi-
dence. The primary exposure Is determined by considering the
location of people relative to roadways. The secondary ex-
posure is determined using a probabilistic approach based upon
the ratio of land areas exposed to various levels of primary
and secondary noise exposure. The primary and secondary ex-
posures are summed to give the total exposure of residents in
a particular area.
C.1.2 Noise Exposure Estimates
Using the model described In Ref. C-l#, estimates of the
nationwide urban noise exposure have been developed. These
are listed in Table C.3 for 1^7H and lybO. As the table
shows, due to Increases in the population and In the number of
vehicles on the road, the number of people exposed to various
levels of roadway traffic noise is estimated to have Increased
by an average of 10 to 15%.
A breakdown of the exposure of people to urban traffic noise
from various roadway types in different size towns is shown in
Table C.4. These data were computed by the NRTNEM model for
19S0 [C-l]. The bulk of the exposure occurs in places of
200,000 people or more. Major and minor arterlais are the
roadway types that contribute the most to roadway exposure.
*Ccmputations were performed in May 1980.
-------
TABLE C.3. U.S. POPULATION EXPOSED TO VARIOUS LEVELS OF
L(jn OR HIGHER PROM URBAN TRAFFIC NOISE.
Number (In Millions) of People*
Prior Estimates (C-2)
Current Estimates(C—1) Streets Freeways
Ldn(dB) 1974 1980 1974 1976 Total
>80
0.1
0.1
0.1
0.4
0.5
>75
0.9
1.1
1.3
0.8
2.1
>70
4.8
5.5
6.9
1.3
8.2
>65
16.3
18.3
24. 3
2.2
26.5
>60
39.3
U3.8
59.0
3-5
62.5
>55
83.O
92.0
93.4
5.4
98.3
* Does not include rural exposure.
-------
TABLE C.I. U.S. POPULATION (IN MILLIONS) EXPOSED TO 55 dB Ldn or HIGHER
FROM URBAN TRAFFIC NOISE, BY PLACE SIZE AND ROADWAY TYPE*.
Urban Place Size (No. of People)
lm
500k
200K
100k
50k
25k
5k
Roadway Type
2rn
-2m
-lm
-500k
-200k
-100k
-50k
-25k
Total
Interstate
3.15
2.01
1.18
1.1 '1
0.59
0.26
0.12
0.21
9.32
Other Highway
2.93
1.15
0.53
0.71
0.16
0.29
0.13
0.21
15.79
Major Arterial
7. 79
2.62
1.88
2.66
1.65
1.20
1.11
2.22
21.13
Minor Arterial
7.78
3.39
2.15
2.91
1.65
1.05
1.11
2.29
22.36
Co I lector
5.61
2.99
2.01
2.01
1.11
0.67
0.96
2.00
17.36
Local
7.51
2.67
1.56
1.91
0.15
0.30
0.11
0.58
15.15
Total
35.07
11.86
9.31
11.73
5.91
3.77
3.87
7.57
92.09
* Data from May 19&0 NRTNIiM.
-------
C.1.3 Comparison with Prior Estimates
In previous work for the EPA (C-2), a population density model
of noise exposure was developed in which the mean L
-------
C.2 Rural Traffic Noise Exposure
Estimates of the noise exposure of people in rural areas are
derived from a special model developed for this purpose rather
than from the E?A NRTNEM model for a number of reasons.
First, the population located near major rural roads must be
known with more precision than a general population density
model can provide. Second, the actual locations of homes
relative to rural roads depends in a complex way on the type
of roadway and the terrain between the road and the home.
Third, rural population densities vary greatly from region to
region; therefore using the national average figures of the
NRTNEM would introduce errors in the total exposure esti-
mates.
The rural model described below requires two major components:
(1.) day-night sound level estimates at varying distances from
each roadway, and {2.) the distribution cf people as a func-
tion of distance for each of these roads.
Day-night sound level estimates are rather straightforward to
obtain because of the availability of noise prediction models
and information about the traffic characteristics on roadways
in rural areas. However, before this study was undertaken,
data that described the distribution of people in rural areas
along rural roadways were not available.
In order to obtain information on the location of residences
relative to rural roadways, ^51 miles cf roadways were sur-
veyed in three different states (described below). From the
resulting distributions, the percentage of dwellings located
within different distance ranges from the roadway were deter-
mined for different roadway and terrain types, for distances
corresponding to various Ldn values. The linear density
C-9
-------
in people per mile of roadway was determined as well. From
these data, estinates of the nationwide noise exposure were
derived, as described in the following section.
C.2.1 Noise exposure model
A recent tabulation of roadway statistics published by the
Federal Highway Administration [C-4] provides information
about the number of miles of roadway in rural areas, classi-
fied by both roadway type and by the type of terrain surround
ing the roadway. This information was gathered from data pro
vided by 46 states. The roadway classifications are inter-
state, other principal arterial, minor arterial, major collec
tor, minor collector, and local. The terrain types are flat,
rolling, and mountainous.
Review of the traffic characteristics of the roadways indi-
cated that the low traffic flow on minor collectors and local
roadways in rural areas would not result in noise exposures o
significant interest in this study, and therefore these roads
were eliminated from further consideration.
For each of the four remaining types of roadways, estimates o
the Ljn at 50 ft were made using the latest modification
of the TSC traffic noise prediction model [C-5]• These sound
levels and the traffic characteristics used to make estimates
are listed ir. Table C. 5- 'There are two sources £or these dat
as indicated in the table. The primary source is a Federal
Highway Administration document that provides statistics from
46 states [C-4], The second source is the EPA study IC-1]
from which the National Roadway Traffic Noise Exposure
-------
TABLE C.5. TRAFFIC CHARACTERISTICS AND DAY-NIQHT SOUND LEVELS
FOR RURAL ROADWAYS.
Hoadway Type APT*
% Truckst
Average Speed
(All Vehicles)
(mph)t
Ldn at 50 ft
(dB)
In tera tates
13,700
17
55-8
77-5
Other Principal
Arterlals Jl, 6 2 jj
14
51.9
72.5
< 1
1
1-1
Minor
Arterlals
Major
Go Hectors
2,523
889
11
50.6
45.8
68.5
62.5
* Source: Kef. C-l
t Source: Hef. C-Jl, for medium and heavy trucks.
-------
Model (NRTNEM) discussed in the last section was developed,
which contains traffic data extrapolated to all of the states-
(Note that the four categories of roadway used here correspond
to the first four categories in Table C.l.) NRTNEM utilizes
different ratios of medium to heavy trucks, depending on the
urban place size, the roadway type, and the year of analysis.
The baseline ratios range from 1:6 for interstates in rural
areas to 7:5 for miner arterlals in urban areas. For most
roadway types and place sizes, an appropriate approximation is
50% medium trucks and 50% heavy trucks. This ratio is assumed
to apply to all roadway types in this model. NRTNEM assumes
that 87X of daily traffic occurs during daytime hours, and .13%
occurs at night. In this application, we have assumed that
30% of the traffic occurs during daytime hours.
C.2.2 Population distribution characteristics
The distribution of residences in rural areas varies consider-
ably. Farm areas would be expected to have a lower density
than non-farm areas, and major terrain differences might also
be expected to contribute to the variability of densities.
Five different areas were chosen for survey purposes: Connec-
ticut (rolling terrain), Central Illinois (flat terrain),
Northern California (mountainous terrain). Central California
(flat terrain), and Coastal California (mountainous terrain).
In each of the five areas, aerial photographs taken before
1977 of several roadways were reviewed. The distance from
individual dwellings to the center of each road was tabulated,
for distances back from the roadway of between 1000 and 2000
ft. Table C.6 lists the roadways and mileages sampled, cate-
gorized by terrain type and type of facility (Interstates and
-------
TABLE C.6. RURAL ROADWAYS SURVEYED.
Plat Terrain Rolling Terrain Mountainous Terrain
Roadway Type CalIfornla 111 lnols Connecticut California
Interstate and
Other Principal Rts.99, 101, 198 1-55
Arterlals 96.1 miles
11.5 miles
1-86
13.4 miles
1-80
50.6 miles
^ Minor Arterlals Rts.'II, 65
»-•
UO
l'/.7 miles
Rts.36, 67, 123 Rts.11, 63
25-8 miles 8.6 miles
Rts.16, 19
105-8 miles
Major
Collectors
lit .216
15.3 miles
Rts.123, 613
15.6 miles
Rt.63
17.3 miles
Rts . 1, 16
72.9 miles
-------
other principal arterlals have beer, grouped together as one
facility type for this classification). Note that every com-
bination of terrain type and facility type was surveyed, with
two sets of data obtained for each facility for flat terrain.
C.2.3 Noise exposure estimates
The distances to L
-------
TABLE C.7 • DISTRIBUTION OP RURAL RESIDENCES BY NOISE EXPOSURE RANQE.
Roadway Type
L(jn Range (dB)
Percentage of Residences Along Roadway
Distances (Ft) Plat Rolling Mountainous
Jnterstatea
70-75
65-70
60-65
55-60
80-160
160-360
360-760
760-1660
15
13
20
15
0
17
50
29
3
31
53
9
Other Principal
Arterlals
70-75
65-70
60-65
55-60
0-80
80-160
160-360
360-760
1
15
13
20
0
0
17
50
0
3
31
53
Minor Arterlal3
70-75
65-70
60-65
55-60
0-10
10-80
80-180
180-100
0
0
11
33
15
11
31
10
15
27
32
21
Major Collectors
70-75
65-/0
60-65
55-60
0-20
20-10
10-80
80-160
0
1
15
32
0
3
36
17
0
7
16
23
-------
TABLE C.8. NATIONAL MILEAGE OP RURAL ROADS AND RESIDENTIAL DENSITY ALONG THEM.
Roadway Type
Terrain Type
Number of Miles
Nationwide
Linear Density In
Resldences/Mlle
Interstate
l'lat
Rolling
Mountainous
15,^29
14 ,190
2,095
1.85
3.71
2.29
Other Principal
Arterlals
Flat
Rolling
Mountainous
31,715
47, 111
6,857
4.85
3.74
2.29
Minor Arterlals
l'"l a t
Rolling
Mountainous
53,042
87,262
15,244
4.29
16.74
3.27
Major Collectors
Plat
Rolling
Mountalnoua
138,930
258,697
37,890
5.38
7-91
1.76
-------
TABLE C.9. LINEAR DENSITY SCALING FACTORS.
Total Rural
Linear Density
(People/Mile of Road)
Scaling
Factor
United States
California
Illinois
Connectlcut
20.5
24.0
IB.9
87.3
0. 85
1.08
0.23
-------
number of people living in rural areas divided by the total
rural mileage), for the nation as well as the three states of
interest [C-4]. From the table, it can be seen that the
linear densities of the rural population in California and
Illinois are not much different from the national rural linear
density; but the density in Connecticut is more than four
times the national density. We can then use the appropriate
state scaling factor, determined by dividing the U.S. density
by the state density, to adjust the linear densities in Table
C.8. These scaling factors are shown in Table C.9.
As an example, the linear density for interstates in flat ter-
rain areas (Table C.9) is adjusted by an average (Table C.6)
of the California and Illinois scaling factors (Table C.9):
4.85 x (0.85 + 1.08)/2 = 4.68 residences/mile. (C.2)
Similarly, linear density for Interstates in rolling terrain
areas is adjusted by the Connecticut scaling factor:
3.74 x 0.23 = 0.86 residences/mile (C.3)
The linear density for interstates in mountainous terrain
areas is adjusted by the California scaling factor:
2.29 x 0.85 =¦ 1-95 residences/mile. (C.4)
Linear densities for the other roadway types are adjusted in a
similar fashion.
Multiplying the adjusted linear density by the national number
of miles for each roadway provides the number of residences
C-l8
-------
along each roadway type. Then, applying the percentage of
residences within each 5 d3 range of day-night sound level
appropriate to the particular facility/terrain type, the
number of residences exposed to various levels of Ldn
nationwide are obtained. For examplej the number of
residences along interstates in flat terrain areas is (from
Eq. C.2 and Table C.8):
4.68 x 15,429 = 72,208 residences. (C.5)
The number of residences in the 70 to 75 dB L
-------
TABLE C.10.NATIONWIDE DISTRIBUTION OP RURAL RESIDENCES BY NOISE
EXPOSURE RANGE.
I.dn Range (dB) Interstate
Number (in Thousands) of Residences
Other Principal
A rterials
Minor
A rterials
Major
Collectors
All
Roads
70-75
65-70
60-65
55-60
11.0
3 'l. 6
22.7
14. 8
1.5
22.7
75.'I
57.1
56.8
159.3
207.3
115.9
0
25.2
284.7
460.7
69.3
241.8
590.1
648.5
-------
TABLE C.ll. U.S. POPULATION EXPOSED TO VARIOUS LEVELS
OP Ldn OR HIGHER PROM TRAFFIC ON URBAN AND RURAL ROADS.
(d3) Number (In Millions) of People
Urban Rural Total
>80 0.1 0.0 0.1
>75 1.1 0.0 1.1
>7C 5-5 0.2 5-7
>65 18.3 1.0 19.3
>60 43.8 2.8 46.6
>55 92.0 4.8 96.8
-------
REFERENCES FOR APPENDIX C
C-l U.S. Environmental Protection Agency, "National Roadway
Traffic Noise Exposure Model," Science Applications Inc.
report prepared for the Environmental Protection Agency,
November 1979-
C-2 W. Galloway, K. Eldred, and M. Simpson, "Population Dis-
tribution of the United States as a Function of Outdoor
Noise Level," EPA Report 550/9-7^-009, June 197^.
C-3 U.S. Environmental Protection Agency, "Background Docu-
ment for Medium and Heavy Truck Noise Emission Regula-
tions," EPA Report 550/9-76-008, March 1976.
C-4 U.S. Department of Transportation/Federal Highway Admin-
istration, "National Highway Inventory and Performance
Study Summary," FHWA-PL-78-006, December 1977-
C-5 U.S. Department of Transportation/Federal Highway Admin-
istration, "Users Manual: TSC Highway Noise Prediction
Code: Mod-0V FHWA-RD-77-lS, January 1977.
C-6 U.S. Department of Transportation/Federal Highway Admin-
istration, "FHWA Highway Traffic Koise Prediction Model,"
FKWA-RD-77-108, December 1S78.
C—7 U.S. Department of Commerce, Bureau of the Census, "Sta-
tistical Abstract cf the United States, 1977," September
1977.
C-22
-------
APPENDIX D. AIRCRAFT NOISE EXPOSURE IN THE COMMUNITY
D.l Noise Exposure Model
The noise exposure estimates listed below were derived from
the model of air carrier aircraft noise exposure described in
P.ef. D-l. The approach taken in that document to estimating
nationwide exposure was to categorize all air carrier airports
Into four "average" airports; calculate the exposure at- each
average airport; and scale the results to the entire nation.
The four categories of airports, termed "AVports," included:
Airports that are candidates for SST operations
Airports .allowing all aircraft except SSTs
Airports where four-engine jets do not operate,
except for LaGuirdia and Washington National
Airports
LaGuardla and Washington National Airports.
For each AVport category, an average runway and flight track
configuration was defined, and average numbers of operations
and fleet mix were determined.
Noise exposure contours were developed for each AVport using
the average data and the Integrated Noise Modal computer pro-
gran [D-l]. Using data from the U.S. census, a population vs
area relationship was developed; application to the area with-
in each noise exposure contour resulted in an exposed popula-
tion estimate for each AVport.
D-l
-------
Finally, these results were extrapolated to the nation using
scaling factors based on relative number of operations among
the various AVport categories. The resulting noise estimates
are shown In Table D.i.
In a subsequent study [D-2], these results were modified to
include revised fleet operational information and population
data and updated noise levels for certain types of aircraft.
The modified estimates are also shown in Table D.I.
As a best current estimate of the nationwide noise exposure of
air carrier aircraft, an average of these two estimates has
been made, as shown in Table D.I.
The estimates of Refs. D-l and D-2 do not provide exposure
data below L
-------
TABLE D.l ESTIMATES OP U.S. POPULATION EXPOSED
TO VARIOUS LEVELS OP Ldn OR HIGHER
PROM AIR CARRIER AIRCRAFT NOISE
Number (In Millions) of People*
Current Estimate In
Ldrt dB Ref.D-l Ref.D-2 Estimate Levels Document
>80 0.05 N/A 0.05 0.2
>75 0.3 0.3 0.3 1.5
>70 1 - 4 1. 2 1. 3 3.L
>65 5.2 4.2 4.7 7.5
>60 N/At N/A 11.5 16.0
>55 N/A N/A 2 4.3 N/A
65 d3 are
values. Values
text.
t N/A = Net available from this Reference.
* Current estimates for L,~n between 33 and
derived from average of Ref. D-l and 3-2
for 55-60 dB are derived as described In
-------
D.2 Comparison with Previous Estimates
The "Levels Document" [D-4] contained earlier estimates of
aircraft noise exposure, for the L^n range of 60 to bO dB,
based on several earlier studies. For comparison purposes,
these estimates are also shown in Table D.l. The CARD study
[D-5] estimated that 1500.square miles were exposed to levels
in excess of an L
-------
REFERENCES FOR APPENDIX D
D-l C. Eartel and L. Sutherland, "Noise Exposure of Civil
Air Carrier Airplanes through the Year 2000," Vol. 1,
WR 78-11, February 1979-
D-2 K. Eldred, "Estimate of the Impact of Noise from Jet
Aircraft Air Carrier Operations," BBN Report 4237,
November 1979«
D-3 K. Eldred, "Aircraft Noise Goals," EPA report to be
published.
D-4 "Information on Levels of Environmental Noise Requisite
to Protect Public Health and Welfare with an Adequate
Margin of Safety," EPA 550/9-74-004, March 1974.
D-5 Joint DOT-NASA "Civil Aviation Research ana Development
Policy Study," DOT TST 10-4/NASA 265, March 1971.
D-6 "Report of the Administrator of the Environmental Pro-
tection Agency," Public Law 91-604, February 1972.
D-7 D.I. Bishop and M.A. Simpson, "Noise Exposure Forecast
Contours for 1967, 1970, and 1975 Operations at Selected
Airports," BEN Report No. 1363, prepared for Department
of Transportation, Federal Aviation Administration Office
of Noise Abatement, September 1970.
D-8 "Aircraft Noise Analyses for the Existing Air Carrier
System," BBN Report No. 331&, submitted to Aviation
Advisory Commission, September 1572.
r> c
L/-D
-------
APPENDIX E. CONSTRUCTION NOISE EXPOSURE IN THE COMMUNITY
In this section, estimates of construction noise exposure are
presented. These estimates are based on the construction
noise model described In the EPA "Background Document for
Portable Air Compressors" [E-l].
E.l Construction Activity Model
Construction activity In the United States involves a wide
variety of equipment, operating conditions, work hours, and
site locations. Some construction equipment, such as the pile
driver, create a great deal of disruptive noise but are only
used at a small fraction of construction sites for a relative-
ly short period of time, primarily during one construction
phase. Other equipment, such as a dump truck, are used in
many types of construction projects from the initial clearing
phase through the finishing phase.
To develop a model of the noise levels produced by each con-
struction site as a whole, the following steps are taken, as
shown in Tables E.l(a)-(d) [E-2j. First, noise levels are
obtained for each of the 22 pieces of construction equipment
that is found to be the most significant component of con-
struction activity In the United Stages. 'Then, four types of
construction are defined, based on the different activities
observed in each type. These are residential, nonresidential,
industrial, and public works. Next, activity at each sire is
divided into five phases: clearing, excavation, foundation,
erection, and finishing. Then, the fraction of the total sire
construction time that each piece of equipment
E-l
-------
TABLE E.l(a). USAGE FACTORS OF EQUIPMENT IN RESIDENTIAL CONSTRUCTION
(197 4) CE—1D.
Equipment
Construction phase
1'eq (.r>0') 'luring work
periods for each item,
over one project
v *
C
rt
s
O
Excavation
Foundation
c
0
1
&
u
t£
to
*c
r.
Air compressor
(31)*
-
0.1
-
-
0. 25
68. 7
Backhoe
(85)
.0.02
0. 2
-
-
0.02
69. 5
Concrete mixer
(85)
-
-
0.4
0.08
0.16
76.5
Concrete pump
(82)
-
-
-
-
-
-
Concrete vibrator
(76)
-
-
-
-
-
-
Crane, derrick
(88)
-
-
-
-
-
-
Crane, mobile
(83)
-
-
-
o
G
0.04
69. 5
Dozer
(87)
0. 10
0. 1
-
-
0.04
72.0
Generator
(73)
0.4
-
-
-
-
64. 5
Grader
(85)
0.05
-
-
-
0.02
65. 0
Pa\inc Breaker
(SS)
-
-
-
-
0.01
61. 0
Loader
(84)
0. 2
0.1
-
-
0.04
70. 0
Paver
(89)
-
-
-
-
0.025
66.0
Pile driver
(101)
-
-
-
-
-
-
Pneumatic tool
(85)
-
-
0.04
0.1
0.04
72.5
Pump
(76)
-
0. 1
0. 2
-
-
63.0
Rock drill
(98)
-
0.005
-
-
-
65. 5
Roller
(80)
-
-
-
-
0. 04
59. 0
Saw
(78)
-
-
0.04[2]r
0.1 [2]
o
o
li-
rr?
68. 5
Scraper
(88)
0. 05
-
-
-
0. 01
67,0
Shovel
(82)
-
0.2
-
-
65. 5
Truck
(88)
0. 04
0. 1
-
-
0. 04
70. 0
Leq (50') per sita during work periods = 82.0 dBA
Hours at site 24 24 40 30 405 = ?0S
= 23 l.!:: . 25
Total number of sites = 514,424 (Table E. 2)
* Numbers in parentheses O represent average A-weighted noise levels at 50
t Numbers in brackets [ ] represent average number of items in use, if that
number is greater than one. Blanks indicate zero or very rare usage.
-------
TABLE E.l(b). USAGE FACTORS OF EQUIPMENT IN NONRESIDENTIAL BUILDING
CONSTRUCTION (1974)[E-1J.
^ e
Construction phase
u 0
0
>
> -
b£ O «
Equipment
C CB ®
•- « 0
u
c
u
te
c
_o
e
o
£
SlC
= ^ I
"c a e-
4)
e-s s
^3 I
es
>
C3
¦o
c
o
U
c
CQ
u
3
Q
o
L-
c
g-u 0
J SJ >
^ c. c
5
W
Uq
w
Air compressor
(81)'
-
1.0[2jt
1.0[2]
1.0[2]
0.4[2]
83. 5
Backhoe
(85)
0.04
0.16
0.4
-
0.04
76. 5
Concrete mixer
(85)
-
-
0.4
0.4
0.16
79. 0
Concrete pump
(82)
-
-
0.08
0.4
0.08
74. 5
Concrete vibrator
(76)
-
-
0.2
0.2
0. 04
67. 0
Crane, derrick
(88)
-
-
-
0.16
0. 04
76, 0
Crane, mobile
(83)
-
-
-
0.16[2J
0.04 [2]
74. 0
Dozer
(87)
0.16
0.4
-
-
0.16
75.0
Generator
(78)
0.4[2]
1. 0[2]
-
-
75. 0
Grader
(85)
0.08
-
-
-
0. 02
63. 5
Paving breaker
(88)
-
0. 1
0. 04
0.04
0. 04
75. 0
Loader
(84)
0.16
0.4
-
-
0. 16
75. 0
Paver
(89)
-
-
-
-
0. 1
70. 0
Pile driver
(101)
-
-
0.04
0.16 [2]
0.04[2]
85. 0
Pneumatic tool
(85)
-
-
0.04
0. 16[2]
O
O
J*-
76. 0
Pump
(76)
-
1.0[2]
1.0[2]
0.4
-
76. 5
Rock drill
08)
-
0. 04
-
-
0. 005
78. 0
Roller
(80)
-
-
-
-
0. 1
60. 5
Saw
(73)
-
-
0.0 4[3]
1.0[3]
-
76. 5
Scraper
(88)
0. 55
-
-
-
-
73. 0
Shovel
(82)
-
0.4
-
-
-
72. 0
Truck
(88)
0. 16[2]
0.4
-
- •
0. 16
SC. 0
Leq(5o() per site during work periods = 91. 0 riP.A
Hours at site SO 320 320 480 160 ^ = 13G0 iirs.
= 170 days
Total number of sites = 12,710 (Table E.2J
* Numbers in parentheses 0 represent average A-weighted noise levels at 50 ft.
* Numbers in brackets [ J represent average number of items if number is
greater than one. Blanks indicate zero or very rare usage.
-------
TABLE E.l(c). USAGE FACTORS OF EQUIPMENT IN INDUSTRIAL CONSTRUCTION
(1974)[E-l].
Construction phase
* E
1- V
|
J* ^
M U "
c rt "
Equipment
u
c
£
C3
0)
c
o
c3
>
cl
u
x
C
o
rt
c
2
o
c
0
O
be
c
"m
c
•r 0 0
3 u 0
—* a
- Cfl c
0 — 0
-
« 0 2
— a 0
U
td
fc
Air compressor
(81)*
_
1.0
0.4
0.4
0.4
78.0
Backhoe
(85)
0.04
0.16
0.4
-
0.04
76.5
Concrete mixer
(85)
-
-
0.4
0.16
0.16
77. 5
Concrete pump
(82)
-
-
0.05
0.16
0.08
71.0
Concrete vibrator
(76)
-
-
0.2
0.1
0.04
65. 5
Crane, derrick
(88)
- •
-
-
0. 04
0.02
70. 0
Crane, mobile
(83)
-
-
-
0. 08
Ti*
O
O
68. 0
Dozer
(87)
0.2
0.4
-
-
0.04
77. 5
Generator
(78)
0.4
0.4
-
-
-
68. 5
Grader
(35)
0. 05
-
-
-
0. 02
62. 5
Paving breaker
(88)
-
0.1
0.04
0.04
0. 04
75. 0
Loader
(84)
0.16
0.4
-
-
0.04
74. 5
Paver
(89)
-
-
-
-
0.12
70. 5
Pile driver
(101)
-
-
0.04
-
-
81. 0
Pneumatic tool
(85)
-
-
0. 04
0.l[3]t
0.04
76. 0
Pump
(76)
-
0.4
1.0[2]
0.4
-
53.0
Rock drill
(98)
-
0. 02
-
-
0.003
75. 0
Roller
(80)
- -
-
-
-
0.1
60. 5
Saw-
(73)
-
-
o.04(2]
0.1 [2]
-
67. 5
Scraper
(88)
0.14
-
-
-
0. 06
70. 5
Shovel
(82)
-
0.4
-
-
0. 06
72. 0
Truck
(88)
0.16[2]
0. 26 [2]
-
-
0. 16
73.5
Leq(50') Per site during work
periods
=
88. 0 dB
Hours at site
80
320
320
480
1G0S =
13G0s.
170 days
Total number of sites = 50,839 (Table E. 2)
* Numbers in parentheses () represent average A-weighted noise levels at SC ft.
r Numbers in brackets [ ] represent average number of items in use, if that
number is greater than one. Blanks indicate zero or very rare usage.
-------
TABLE E.i(d). USAGE FACTORS OF EQUIPMENT IN PUBLIC WORKS (STREETS,
SEWERS, ETC.) (1974) [E-l].
* S
1- c?
Construction phase
0 a
>
EC*1
Equipment
c
o
c
o
C
I
* 0 £
4 % *
0
c
L.
C3
"3
5
S3
¦e
e
0
T5
£
79.0
Backhoe
(85)
0.04
0.4
-
0.16
74. 5
Concrete mixer
(85)
-
- .
0.1G[2]
0.4 [2]
0.16 [2]
S1.0
Concrete pump
(82)
-
-
-
-
-
-
Concrete vibrator
(76)
-
-
-
-
-
-
Crane, derrick
(88)
-
0. 1
0.04
0.04
-
74.0
Crane, mobile
(83)
-
-
-
0.16
-
69.5
Dozer
(87)
0.3
0.4
0.2
-
0.16
79. 5
Generator
(78)
1.0
0.4
0.4
0.4
0.4
75.0
Grader
(85)
0. 08
-
0.2
0.08
74.0
Paving breaker
(88)
0.5
0. 5
-
0.04
0. l[2]
80.5
Loader
(84)
0.3
0.3
0,2
-
0.16
76. 0
Paver
(89)
-
-
0.1
0. 5
-
81. 5
Pile driver
(101)
-
-
0.04[2]
-
-
-
Pneumatic tool
(85)
-
-
0.1
0.04
72. 5
Pump
(76)
-
0.4[2]
1.0[2]
0.4[2]
-
75.5
Rock drill
(98)
-
0.02
-
-
-
32. 5
Roller
(80)
-
-
0.01
0. 5
0. 5
/ . 5
Saw
(78)
-
-
0.04 [2]
n. 114
-
63. 5
Scraper
(83)
0.06
-
0.2
0.08
0.08
78. 0
Shovel
(82)
0.04
0.4
0.04
-
0.04
71. 0
Truck
(88)
0.16(2]
0.16
0.4 [2]
0.2 [2]
0.16 [2]
84. 5
^eq(50')
per site during work periods
=
91.0 dR
Hours at site:
12
12
24
24
12£ =
84 hrs.
10 \ day
Total number of sites
= 485,224 (Table E.2)
* Numbers in parentheses Q represent average A-weighted noise levels at SO rt.
Numbers in brackets [ ] represent average number of items in use, if that
number is greater than one. Blanks indicate zero or very rare usage.
-------
spends In Its normal operating mode is estimated for each
phase, and a corresponding site duration equivalent noise
level (Leq) is computed. Finally, these Leq's for each
piece of equipment are logarithmically summed to yield an
average site Leq for that type of construction.
For each of the four types of construction sites in Tables
E.Ka) through E.l(d), the Leq (at 50 ft) for an 8-hour
work period is calculated, and the time at each work site is
shown. The number of work sites Indicated in the table is
based on 1970 metropolitan construction activity shewn in
Table E.2 [E.l]. The sound level data came from open litera
ture, manufacturers' reports, and EFA-solicited measurements
E.2 Population Distribution
An EPA report (NTID 300.1) [E-2] inclu~.es da^a on the popula-
tion distributior. for various regions These data are summa
ized in Table E.3.
The data from Tables E.2 and E.3 are used to determine the
average population density in the neighborhood of different
types of construction. The average population density ( p),
weighted by the number of sites in each region, Is calculate
with the following equation [E-l]:
where Sn is the number of construction sites of a given type
in metropolitan region n, pn is the daytime population den-
sity in region n, and 5 is the total rumoer. of construction
sites of a given type. The results of this calculation are
shown ir. Table E.4.
E. 1
-------
TABLE E.2. ANNUAL CONSTRUCTION ACTIVITY IN METROPOLITAN REGIONS FOR 1970 [E-l].
Number of Sites
Metropolitan Regions
Targe high-density
central cities
Large low-density
central cities
Other central cities
i
Urban fringe
Met. area outside
urban fringe
Totals
Residential
Buildings
0,700 *
21,570 t
102,559 +
262,000 f
110,779 t
51'l ,'I2'I *
Nonresidential New Municipal
and Industrial Streets, Sewers
Buildings*** And Water Lines
Replacement
of Sewers
And Water Lines
1,952 *
'1,903 t
12,021 t
30,915 1
13,750 i
63,5'I9 *
2,104 **
17,200 t
'10,000 **
9'I,'I00 t
173,600 I
335,30'! [E-4]
1,000
«*
7,920 **
21,600 **
'10,520'**
70,000 **
1'19,010 ft
* Reference [K-3J and unpublished data from the U.S. Bureau of Census.
Apportioned by population density.
** Apportioned through a correlation developed at BBN for 2'l cities, relating miles of street per
square mlLe to population density; assumed constant ratio of miles of new road to miles of
existing roadt assumed 0 sites per mile.
II Extending trend for Boston area to 550,000 miles [E-5] of existing road: 2% of existing road
mileage for water lines, 1.5% of existing mileage for sewers, 0 sites per mile.
*** 00% assumed to be Industrial Buildings, 20% Nonresidential Buildings.
-------
TABLE E. 3. GEOGRAPHIC DISTRIBUTION OF POPULATION AND POPULATION DENSITY (1 970)[E-lJ
in
i
Co
Region
Population
t
Area
(sq miles)
[E-6]
Nighttime
Population
Density
(people per
sq miles)
Daytime
Population
Density
(people per
sq mile)
«*
Population
Density
(people per 1/8
linear inile)
**,++
12 Large filgh-denslty
central, cities
22 ,250,000
1 ,'168
15,160
16,650
120
l'l Large low-density
central cities
10,530,000
2,389
'I,'I10
t),860
10
l86 Other SMSA's *
25,820,000
6,981
3,710
*1,070
32
Urban fringe
'19,680,000
l1' ,707
3,380
3,100
21
Met. area outside
urban fringe
22,320,000
179,276
125
111
-
'IV)Lal population in or* near cities = 130,600,000.
* .'standard Metropo 11 tan Statistical Areas - groups of contiguous counties which contain at least
one central city of 50,000 Inhabitants or more, or "twin cities" with a combined population of
50,000 or more.
I Population fl^ires were extrapolated from I960 Census figures [E—7] according to recent growth
rates.
** Takes into account the net population transfer from the suburbs to the central city during the
normal working day. This net transfer was derived from I960 Census figures [E-7l adjusted to
1970 according to recent population growth.
1i Made use of a correlation developed at BBN for 2'l cities, relating miles of street per sq mile
to population density.
-------
TABLE E.4.
AVERAGE POPULATION
DIFFERENT TYPES OF
[E-l].
DENSITIES EXPOSED TO
CONSTRUCTION ACTIVITY
Residential Nonresidential Public Works
Buildings Buildings and Highways
Average Population
Density,
people per sq mile 2907 3139 1866
-------
E.3 Noise Exposure Estimates
Population exposure to construction activity noise is deter-
mined by combining the construction site and population densi-
ty data described in Tables E.l and E.U.
For each construction site, it is assumed that all the noise
sources may be combined at one location as a point source.
For most sites, a 6 dB per doubling of distance dropoff rate
is used from that point to determine the distance at which the
L,jn level for the site is 55 dB. For nonresidential
building construction sites, because of their size, a 3 dB per
distance doubling dropoff rate out to 40C ft was assumed, and
6 dB per distance doubling thereafter. It is also assumed for
all sites that the first IOC ft around the site centerpoint is
unoccupied by the public. Using the distance where the
is equal to 55 d3, the land area exposed to an Ldn
of 55 d3 or greater for each type of construction can be
determined. Multiplying this land area by the average popula-
tion density around each site, the number of people exposed to
an Ldn of 55 dB or greater is determined. It is assumed
that at each construction site, except the office site, only
one-half of the nearby building occupants are exposed to con-
struction noise. For office sites, the number of people is
reduced to 2 5%; for such sites, the neighboring buildings are
mostly office buildings in which only approximately one-
quarter of the occupants are exposed to construction noise
from the adjacent site.
The population noise exposure calculations are summarized in
Table Z.5. Included in Table E.5 is the annual L^r. at 50
ft, the radial distance to 55 dB L
-------
TABLE E.5. CALCULATION OF POPULATION IMPACTED BY ANNUAL Ldn GREATER THAN 55 dB.
Current Levels
8-hr Lfeq (50 ft)
Average Days of Activity Per Year
Annual Outdoor L^n ('50 ft)
Distance Required for Attenuation
to 55 dfc
Area Within Radius (Excluding
first 100 ft)
Average Population Density
for Site
Percent of Population Impacted
People Tirpacted Per Site
(Rounded)
Total. Number of Sites
Total Population Impacted
(Rounded)
Nonresidential Street and
Residential Building Industrial Sewer
Construction Construction Construction Construction
82 dB
26
65.8 dB
173 ft
50
3
5lM2'l
1,700,000
91 dB
170
82.9 dB
3512 ft
88 dB
170
79.9 dB
879 ft
91 dB
10-1/2
70.8 dB
308 ft
0.002 sq mile 1.39 sq mile 0.09 sq mile 0.010 sq mile
2907/sq mile 3l89/sq mile 3l89/sq mile 1866/sq mile
25
1396
12,710
1^,100,000
50
137
50,839
7,000,000
50
9
485,22k
4,300,000
-------
people exposed to 55 dB (or greater) for each type of con-
struction. In a similar manner, the number of people exposed
to L
-------
Report No. 3318R
Bolt Beranek and Newman Inc
TABLE E.6 U.S. POPULATION EXPOSED TO VARIOUS LEVELS
OF Ldn OR HIGHER PROM CONSTRUCTION NOISE
Number of People In Millions
Lhn (d3) Residential Non-Resldentlal Total
>75 0.1 C.l
>70 0.6 C. 6
>65 2.1 2.1
>60 1.0 6.7 7.7
>55 6.C 21.5 27.5
-------
APPENDIX E REFERENCES
E-l "Noise Emission Standards for Construction Equipment,
Background Document for Portable Air Compressors," EPA
Report 550/9-76-004, Washington, DC, December 1975.
E-2 Bolt Beranek and Newman Inc., "Noise from Construction
Equipment and Operation, Building Equipment, and Home
Appliances," prepared for the Environmental Protection
Agency, Report No. NTID 300.1, 31 December 1971.
E-3 Business ana Defense Services Administration, "Construe
tion Review," April 1971.
E-4 U.S. Department of Transportation, Federal Highway Admi
istration," Highway Statistics/1969, Washington', D.C.
E-5 Bolt Beranek and Newman Inc., "Specialty Construction
Trucks: Noise and Cost of Abatement," BBN Report No.
2566e, September 1973-.
E-6 Homer Hcyt, "Urban Land Use Requirements 1968-2000,''
Homer Hoyt Institute, The American University, Washing-
ton, D.C., Research Monograph No. 1, 1968.
E-7 U.S. Department cf Commerce, Bureau of the Census, "Cen
sus of Population: I960."
-------
APPENDIX P. RAIL NOISE EXPOSURE IN THE COMMUNITY
In this appendix, noise exposure estimates are developed for
three distinctly different types of rail operations: railroad
line operations, rapid transit operations, and rail yard oper-
ations .
P.l Railroad Line Noise
F.1.1 Noise exposure model
The analysis of current noise exposure from railroad line
operations in the United States is excerpted from the EPA
Background Document for the noise emission standards for rail-
roads [F—1].
According to this report, the national average train opera-
tions for urban areas are as follows:
4 freight trains per day, 2 per night, each 33 mph,
70 cars, 3 locomotives
2 passenger trains per day, 1 per night, each 36 mph,
6 cars, 1 locomotive.
Since the noise of passenger trains is about 10 dB lower than
the noise of freight operations, passenger operations are
omitted in the following analysis.
F.1.2 Noise levels and transmission path
The sound exposure level, LS) for locomotives and rail cars
at 100 ft is given by [F-l]:
F-l
-------
Ls = 11° - 10 log v + 10 log n for locomotives (P.l)
= 33 + 30 log v + 10 log t for rail cars, • (F.2)
where v = train speed in mph
n * number of locomotives
t = rail car passby time in seconds.
For a train with a speed of 33 mph, 3 locomotives, and a
passby time of 73 seconds (70 cars x 50 ft/car + 48 ft/sec),
then Ls = 100 d3 for locomotives and = 57 dB for rail cars,
for a total Ls of [F-l]:
Ls = 10 log (101C0/1C + 1097/1C) = ]_02 dB. (F - 3)
The day-night sound level 100 ft from the track can be
expressed as [F-l]:
Ldn " Ls + 1° l°g CNd + 1° Nn) - (F.4)
where Nj and Nn are the number of daytime and nighttime
operations, respectively. For Ls = 102, = 4, and Nn
= 2, Ljjr_ = 66 dB.
The noise propagation model for railroad noise utilized in
Ref. F-l is based upon a decrease of 4.5 d3 per doubling of
distance from the tracks. In addition, it is assumed that
there ls noise shielding due to struetures and other obstacles
amounting to k.5 dB somewhere in the first 500 ft. The net
attenuation can be approximated by a straight-line dropoff of
6 d3 per doubling of distance.
F-2
-------
P.1.3 Noise exposure estimates
Prom this attenuation model, the values of prevailing
In strips of land along the track can be determined. Por
example, if L(jn = 66 dB at 100 ft, at 200 ft, L^n * 60
dB (for a 6 dB per distance doubling attenuation). Similarly,
for the 8000 miles of U.S. railroad track and a population
density along this track of 2500 people per square mils [F-i],
Table F.l illustrates the means for determining the population
exposed to various 5-dB ranges of L^n.
TABLE P.l DETERMINATION OP POPULATION EXPOSURES.
Distances of Width of Aggregated Area
L Range Strip Boundaries Strip on of Strips Population
n(dB) from track one side of in US (millions)
(ft) track (ft) (sq mile)
65-70 65-116 51 155 0.3b7
60-65 116-207 91 276 0.690
55-60 207-367 160 485 1.213
The total numbers of people In the United States exposed to
railroad noise at various Ldn levels or higher are
provided in Table P.2.
-------
TABLE F.2. D.S. POPULATION EXPOSED TO VARIOUS LEVELS OP
Ldn OR HIGHER PROM RAILROAD NOISE.
^dn ()
Number (in Millions) of People
>65
>60
>55
0.39
1.08
2.2S
P.2 Rail Rapid Transit Noise
P.2.1 Noise exposure model
Wayside noise level and population data for the nine major
U.S. rail rapid transit systems are available in the litera-
ture [F-2, F-3, F-4]. These data are summarized in Table 7.3
for surface operations and ir. Table 7.4 for operations on ele-
vated structures. The data are used to estimate noise impact
due to rail rapid transit operations as described below.
Noise impact is described in terms of the number of people ex-
posed to various values of the day-night average sound level
resulting from rail rapid transit operations. 3iven
the transit system L^n data from Tables F.3 and an
attenuation rate of 3 d3 per doubling of distance is used to
determine the distance to contours of 70 dEj 65 dB, 60 dB, and
55 dB for each transit system. The background ambient noise,
defined here as the Ldn ^o sources excluding train
passages, is estimated by using the relation
-------
TABLE P. 3. SURFACE OPERATIONS NOISE DATA FOR RAIL RAPID TRANSIT [F-2].
*Jdn
Metropolitan Transit at 50 ft
Region System (dB)
Atlanta MARTA 51*
San Francisco BART 68.5
Chicago CTA 75-5
Boston MBTA 72.3
New York NYCrA 75-'I
Philadelphia PATCO 63.3
Cleveland RTA 75
Philadelphia SEPTA 72.9
Washington, DC WMATA 6*1*
Percent of
Pop. Percent of Surface Operation
Density Surface Operation With Residential
(people/sq miles) (miles) Land Use (?)**
3,316*
5.7t
50 (estimated)
9,165
27.7
37.1
30.9H0
39.8
25.3
21,180
19.5
21.8
51,000
22.7
50
6,100
9.3
39.7
11,470
17.3
18
31,100
1.1
30.9
6,310*
12.5t
10 (estimated)
* See Ref. F-3.
t See Ref. F-1.
**Based on either actual or zoned land use.
-------
TABLE P.I. ELEVAUD OPEJiATIONS NOISE DATA FOR RAIL RAPID TOANSIT [F-3].
Metropolitan
Region
Atlanta
San Francisco
Chicago
Boston
New York
Philadelphia
Cleveland
Philadelphia
Transit
System
MARTA
BART
CTA
Mlfl'A
NYCTA
PA'ITO
RTA
SEPTA
Type of
Elevated Structure*
Concrete (without noise barrier)
Concrete (with noise barrier)
Conrete
Steel (Open Deck)
Concrete
Cone re te/S tee1
Steel (Qpen Deck)
Ldn
50 ft (dB)t
61
57
68
81
72
68
81
Steel (slid web gliders, open deck) 85
Steel (lattice web girders, open
deck) 81
Concrete Viaduct 73
Concrete Encased Steel 69
Concrete
Steel/Concrete
Concrete Viaduct
69
76
73
Length of
Elevated Operation
(miles)
0.5
1.2
20.0
31.5
1.0
1.2
il.il
57
0.3
5.6
0.8
0.9
0
7-2
0.5
Washington,IK
WMATA
Concrete/Steel
67
1.5
*See Ref. F-3 for detailed description,
tEstimated for average system speed and train length.
-------
Ldn = 10 log (p) + 22 dB,
(?.5)
where © ¦ population density (people per square mile). Using
the background noise estimated for each transit system route,
the distance from the tracks where the transit system Ldn
reaches a level 5 dB below the ambient is determined. This
distance, within which the transit system adds more than 1 dB
to the ambient noise environment, is chosen as the limit for
considering population exposure to transit noise. In certain
cases (e.g., densely built-up areas), population is limited to
the first row of buildings.
Population exposure at each sound level is estimated from
phys .cal inventories, where available IF—3]- In the absence
of such information, the population density is distributed
uniformly in each area bounded by the L
-------
TABLE P.5. U.S. POPULATION EXPOSED TO VARIOUS LEVELS OP OR HIGHER
PROM SURFACE OPERATIONS OP RAIL RAPID TRANSIT.
en
Metroj>olitan
Region
Atlanta
San Francisco
Chicago
Boston
New York
Philadelphia
(M eveland
Philadelphia
Washington, DC
'IVansit
System
MAHTA
bant
CTA
MBTA
NYCTA
PATCO
RTA
SE1TA
WMATA
70 dB
0
0
10,500
1,700
20,100
0
1,300
200
0
Number of People Exposed to L^n or Higher
65 dB 60 dB
0
2,000
33,100
5,300
63,600
0
'1,300
600
0
0
6,100
33,100*
16,700
63,600*
500
13,500
600*
200
55 dB
0
20,100
33,100*
16,700*
63,600*
1,500
13,500*
600*
600
* Ambient L(-jn greater than transit L^n minus 5 dB; no further population exposure to
transit noise assumed.
-------
TABLE P.6. U.S. POPULATION EXPOSED TO VARIOUS IZVHLS OP 1^ OR HIGHER
PROM ELEVATED OPERATIONS OP RAIL RAPID TRANSIT.
Metropolitan
Region
Transit
System
70 dB
Number of People Exposed to L^ or Higher
65 dB 60 dB
55 dB
Atlanta
MARTA
0
0
0
50
San I'Vanclsco
BART
30
1,500
8,900
17,700
Chicago
CTA
77,700
77,900
77,900*
77,900*
Itoston
MBTA
800
1,500
2,100
2,100*
New York
NYCTA
2^6,000
252,600
252,600*
252,600*
Philadelphia
PATCO
20
100
300
H00
Cleveland
RTA
—
—
—
—
Philadelphia
SIvFI'A
27,800
27,800*
27,800*
27,800*
Washington, IX)
WMATA
0
0
0
0
* Ambient Lfjn greater than transit L(jn minus 5 dB; no further population exposure to
transit noise assumed.
-------
TABLE P. 7. U.S. POPULATION EXPOSED TO VARIOUS LEVELS OF
Ldn OR HIGHER PROM U.S. RAIL RAPID TRANSIT SYSTEMS.
Number (In Thousands) of People
Lrin(d3) Elevated* Surface Combined
>70 352 3^ 386
>65 361 109 ^70
>60 37C 135 505
>55 379 150 529
~F.ef. F-3.
-------
P.3 Rail Yard Noise
F.3.1 Noise exposure model
Estimates of the nationwide noise exposure due to rail yard
operations are taken from the EPA Background Document for the
final revision to the Interstate Rail Carrier Noise Emission
Standards [F-5]. The model Involves:
1. Categorization of all rail yards by type and
level of activity
2. Estimation of the number of people exposed to
d-ifferent Ldn levels at each of more than 200
rail yards for which noise source, activity infor-
mation, yard configuration, and vicinity
demographic data are available
3. Extrapolating these noise exposure estimates to
all the yards in the country.
Rail yards are first categorized by type (hump or flat),
function (classification, industrial, or small industrial),
and activity rate (high, medium, or low traffic). This
breakdown leads to the following eight categories:
High traffic hur.p classification yards
Medium traffic hump classification yards
Low traffic hump classification yards
High traffic fiat classification yards
Medium traffic flat classification yards
Low traffic flat classification yards
Industrial flat yards
Small industrial flat yards.
-------
These yard categories have different configurations, traffic
volumes, and noise sources and thus different resulting com-
munity noise exposures as well.
The noise sources occurring in various yard types and func-
tions are listed in Table F.b. In general, these can be clas-
sified as either stationary sources or moving sources. For
these sources, the sound exposure level, Ls, can be calcu-
lated as follows:
HD
Ls = ^ave max + 10 log , for moving sources (P.6)
Ls * Lave max + log tefor stationary sources (F.7)
..here
Lave max = average maximum A-weighted sound level
during an event or work cy^le, in d3,
D = shortest distance between sta-..cnary observer and
source path, in ft,
V ¦ source speed, in ft/sec
teff = effective duration, in sec.
The one-hour equivalent sound level, Leq(l), ls related to
the sound exposure level, which is referenced to 1 sec by:
Lec(l) 3 Ls + 10 log (1/3600 sec/hr) = Ls - 35«6. (F.8)
Depending upon the operating characteristics of the source,
the following expressions can be used to estimate the day-
night sound level from each:
Ldn " Ls + 10 log C N (H + 10 Nn> - ±9^, (7.9)
F-12
-------
TABLE P.8. RAIL YARD NOISE SOURCES.
HUMP YARDS:
Master Retarders (Includes Group, Intermediate,
and Track)
Hump Lead Switchers
Inert Retarders
Makeup Switchers
Car Impacts
Idling Locomotives
Locomotive Load Test
Refrigerator Cars
Industrial and Other Switchers
Outbound Trains (Road-Haul plus Local)
Inbound Trains
PLAT CLASSIFICATION YARDS:
Classification Switchers, both ends of yard
Car Impacts
Inbound Trains
Outbound Trains (Road-Haul plus Local)
Idling Locomotives
Load Tests
Refrigerator Cars
INDUSTRIAL AND SMALL INDUSTRIAL YARDS:
Switch Engines
Car Impacts
Inbound Trains (Local)
Outbound Trains (Local)
TO?C/CCFC YARDS (ATTACHED TO ABOVE RAILYARDS)
- Crane/Lift
Hostler Truck
-------
where and Nn are the number of daytime and nighttime
events, respectively, or
Ldn = Leq(D + 1° log (Nd + 10 Nn) - 13.8, (P.10)
when N(j and Nn are the number of daytime and nighttime
hours, respectively, that the source is operating.
The EPA's Environmental Photographic Interpretation Center
(EPIC) analysed the photographic imagery and U.S. Coast and
Geodetic Survey Maps of 207 railyards, selected to represent
the total of 4i69 yards in the country. This analysis
provided data concerning yard configuration and noise source
location at each yard, land use type around each yard, and
distances from rail noise sources to residential and
commercial areas.
Further, a questionnaire was sent to the railroads that owned
the sample railyards, soliciting data on types and number of
sources at each yard, relative source location, and activity
rates for each source.
P.3«2 Noise emission levels and transmission path
characteristics
Table P.9 lists the noise levels at 100 ft for the railyard
noise sources considered as each yard. Substituting these
noise levels and associated activity levels in Eqs. P.9 and
F.10 yields the Ldn for each source at 100 ft.
The L^n at residential and commercial locations in the
vicinity of each yard is determined from
^dn 3 ^dno ~ -og( ^ )n - k]_(D - D0) - 2— ^ 3 - - - -1 '•
F-1L
-------
TABIiE P.9. RAIL YARD SOURCE NOISE IEVEL SUMMARY.
Noise Source
Number of
Measurements
Level of Energy Average*, 100 ft Ifeqd) or
Lave Lmax Lj^it 100 ft
(dD) (dB) (dB)
Mister Retarder: Group,
Track, and Inter-
mediate '110
Inert Retarder 96
Mat Yard Switch Ffriglne
Accelerating 30
Iluiip Switch Ehglne,
Constant Speed
Idling Locomotive 27
55
Car Jrrpact 161
Refrigerator Car 27
load Test (Throttle 8) 59
Crane Lift
Hostler Truck
111
93
77
78
65
(<2500 hp)
67
(>2500 hp)
99
67
87
79
65
111
93
90
90
65
67
99
73
90
83
82
108 (teff=0*5 sec)
90 (teff=0.5 sec)
91 (v=*l mph or 6 ft/sec)
95 (v=1 mph or 6 ft/sec)
66 (constant average level)
9^ (fceft^.3 sec)
67 (constant level)
87 (constant level)
106.5 (teff^lO mln)
91.5 (teff=15 mln)
*A-welghted: love = w°rk cycle or position average for Intermittent or moving sources.
'fiiax = average or expected maxlmim noise level during an event or work cycle.
-------
where
^dno ^dn (100 ft), d3
D0 = 100 ft
n = 1 for moving sources
2 for stationary sources
= combined air and ground absorption coefficient
in dB/ft
k2 = industrial structures insertion loss
1*3 = residential structures Insertion loss.
The Jcj_ value is a function of the spectral characteristics
of the noise sources. The values of <2 and ^3 depend on
the land use and average population density, respectively, in
the vicinity of the yard.
P.3-3 Population distribution characteristics
Around each yard, a rectangular study area was defined extend-
ing the length of the yard and out a distance of 2500 ft on
both sides of the yard for most of the yards (a distance of
5000 ft on both sides was used for large classification
yards). For all 2C7 yards, the estimated 1930 population
within the study area (extrapolated from 1970 census figures),
was divided by the area of the rectangular region (excluding
the area of the rail yard). The resulting average population
density, in people per square mile, was used to estimate the
population noise exposure around each yard, as described in
the next section.
-------
F.3'4 Noise exposure estimates
A computer program has been developed to perforin the necessary
noise exposure calculations. For each yard, the following
information is utilized by the program:
Rail source noise emission levels (from Table F-9)
Rail source activity information (from the yard
questionnaires)
Rail yard configuration/source location (from the
yard questionnaires and EPIC analysis)
Distances to residential and commercial land use
(from EPIC analysis)
Population density around the yard (from the popu-
lation analysis).
For each source, the L^n is calculated at different dis-
tances using Eqs. F.9, F'.IO, and F.ll.
For example at 1000 ft from a master retarder through which
1000 cars are classified each day, if each car generates a
squeal, from Eq. F.9 and Table F.9:
Ldn (100 ft) - 108 + 10 log(850+10x150) - 49.4
= 92.3 c3
where 853 daytime operations have been assumed.
If there are no structures between the master retarder ana the
observation point (i.e., k2 and k3 = 0), and a value of
.01 is used for k]_, from Eq. F.ll:
-dr. (1000 ft) = 92.3-iC iog:^^0 * - .01(1000-100}
= 63-3 d3
F-17
-------
The total L(jn is determined by summation of the Ldn
values for all sources. Using the distances to various total
Ldn values (e.g., 55, 60, 65, 70, and 75 dB) and the
population density, the number of people exposed to different
levels of L
-------
TABLE P.10. DISTRIBUTION OP RAIL YARDS BY YARD TYPE AND
TRAFFIC RATE.
Yard Type
Hump
Classification
Plat
Classification
Industrial
Small Industrial
Number of Rallyards
Traffic Rate
Low Med High Total
46 47 31 124
571 357 185 1113
1381
1551
TOTAL
4169
-------
TABLE P.11. U.S. POPULATION EXPOSED TO VARIOUS LEVELS OF
Ldn OR HIGHER PROM RAILROAD, RAIL RAPID TRANSIT
AND RAIL YARD NOISE.
Lry (d3)' Number (in Millions) of People Exposed
Railroad Rail Rapid Transit Rail Yard Total
>70 — 0.4 0.M 0.8
>65 0.4 0.5 1.6 2.5
>60 l.i 0.5 1.9 3.5
>55 2.3 0.5 3.2 6.0
?-2 0
-------
REFERENCES FOR APPENDIX F
F-l U. S. Environmental Protection Agency, "Background
Document for Railroad Noise Emission Standards," EPA
Report No. 550/9-76-005, December 1975-
F-2 G. Chisholra et al., "National Assessment of Urban Rail
Noise," U.S. Department of Transportation, Report No.
UMTA-MA-06-0099-79-2, March 1979.
F-3 D.A. Towers, "Noise Impact Inventory of Elevated Struc-
tures in U.S. Urban Rail Road Transit Systems," U.S.
Department of Transportation, Report No. UMTA-MA-}6-
0099-80-5, September 1980.
Modern Railroads: 1980 Clty-3y-Clty Transit Dlges
May 1980.
F-5 U. S. Environmental Protection Agency, "Background Docu-
ment for Rail Carrier Noise Emission Standard - Railyard
Facility Emissions and Additional Sources," 18 August
1980, Draft.
F-21
-------
APPENDIX G. INDUSTRIAL NOISE EXPOSURE IN THE COMMUNITY
G.l Noise Exposure Model
The noise exposure in communities with neighboring industrial
operations Is considered as the sura of the individual expo-
sures from every separate Industrial facility. To discuss
this nationwide noise exposure In manageable terms, it is
necessary to compute an estimate of exposure for a simplified
plant-neighbor relationship and then extrapolate the results
to produce estimates of total U.S. population e-xposure.
Calculations are based on
The acoustic power emitted by the industrial plant
which is a function of the electrical energy used by
that plant.
The day-night sound level distribution around the
plant, L
-------
The day-night sound level distribution corresponding
to the radiated acoustic energy of a plant
The local population density.
The method does not include the exposure, assumed to be small,
for onlookers—for example, people walking past an industrial
plant. The noise exposure incurred by people working at these
plants (occupational noise exposure) is discussed in Appendix
X.
G.2 Noise Emission Levels
Individual industrial plant noise sources could be classified
into categories, such as noise-generating process, industrial
use, or sound power level, etc. Ultimately, all industrial
plant major noise sources could be identified ana listed this
way. Such a listing is not presently available.
Prom a neighbor's viewpoint, noise sources can be grouped as
to location, interior or exterior. Interior noise can be
transmitted to a community through building openings—windows,
doors, louvers—or by building walls. Interior noise trans-
mitted :o the community not only results in a transmission
less (usually greater than 10 d3), but often a loss of the
identity of individual sources as well. Exterior sources are
more frequently audible and identifiable in nearby communities
than are interior noises.
Ranges of industrial machinery noise levels are shown in Table
G.l [G—1:. '
-------
TABLE 0.1.
RANGE OP INDUSTRIAL MACHINERY,
EQUIPMENT AND PROCESS NOISE LEVELS [G-l].
A-Welghted Noise Level
Source at Operator Position dB
Pneumatic Power Tools*
Molding Machines
Air Blown-Down Devices
Blowers and Pans
Air Compressors
Metal Forming Machines
Combustion Furnaces
Turbo-generators
Pumps
•Industrial Trunks
Transformers
90-116
101-106
91-104
79-100
93-100
<31-97
81-97*
89-91*
80-91
39-90
83-34
* Measured 2 5 ft from source,
t Measured 10 ft from source.
-------
Published data for fan noise and cooling towers [G-2, G-3] are
supplemented by additional prediction methods [G—4j based on a
review of Individual machinery measurements conducted over the
past 25 years. A representative mix of pumps, compressors,
gearboxes, electric motors, dlesel engines, fans, and cooling
towers was chosen to produce an idealized prediction formula.
The relationship between acoustic power and electric power
energy consumption, chosen as representative for United States
industry, is:
FWL(A)* =88+10 logio hp. (G.l)
0.3 Source Operating Characteristics
Many plants operate only one shift five days per week, while
others, such as electric generating stations, often operate
around the clock seven days per week. Based on discussions
with individual utility companies, a schedule assumed for this
analysis Is an idealized plant operating 24 hours each day for
six days a week.
G.4 Transmission Path
The transmission path between industrial sources and their
neighbors can take many forms. Interior noise from well-
enclosed plants with masonry or metal insulated walls can
suffer transmission losses of at least 15 to 30 cB. Certain
industrial plants, such as oil refineries, open electric
* Referenced to 10-12 watt.
-------
generating stations, and aircraft assembly plants that are
located in warm climates, have few or no enclosing walls. For
this analysis, it is assumed that half the plants contain ex-
terior noise sources only and half contain interior noise
sources only. The latter will be considered to have a radi-
ated sound level 15 dB less than that for the exterior noise
source.[G-7]
Of the 320,700 industrial establishments [1972 total] in the
United States [G-5], it is assumed that most are located rea-
sonably close to the labor force within urban areas of the
country. It Is further assumed that Industrial plants are
often clustered together, partially shielding each other from
residential neighbors. Also, industrial plants are often lo-
cated along transportation routes, such as rivers, highways,
or rail lines. The transmission path t-?tween industrial
sources and their neighbors can have significant shielding
within uninhabited Intervening land areas. To estimate the
fraction of acoustic power that is radiated toward residential
areas, it seems reasonable to consider an industrial park with
16 Industries arranged in a 4 x 4 matrix (see Pig. 3-1). For
the four industries on the corners, one-half of their proper-
ty borders other industries and one-half borders the outside
residential neighbors. The four industries in the center of
the matrix have no common borders with the outside, and the
remaining industries have one-fourth of their property border-
ing the outside. The average fraction of property bordering
residential neighbors is, then, one-fourth, or 25%, in this
example. Industrial areas with smaller numbers of industries
grouped together have a greater percentage of common borders,
while areas with more industries have a smaller percentage of
common borders. However, in this analysis, it is assumed that
one-quartar of the acoustic power from industrial facilities
radiates toward inhabited areas.
-------
Industry r
Percent of Border j Number
Focing Community | of Industries
1, 4, 13, 16
50 4
2, 3, 5, 8, i 25 i 8
9, 12, 14, 15 j
6, 7, 10, 11
0 : 4
Average
25
16
FIG G 1 SCHEMATIC REPRESENTATION CF FRACTION
OF INDUSTRIAL NOISE IMPINGING ON
COMMUNITY .
G-fr
-------
It will also be assumed that shielding, from structures and
other obstacles, amounts to 6 dB between plants and neighbors
and that plant noise in urban areas decreases 6 dB per doub-
ling of distance.
G.5 Population Distribution
The fraction of industrial plants that are located in urban
areas is not known. In 1970, about 66% of the United States
population lived in urban places with a population of 2500 or
more, and 74% lived in all urban places [G-5]. Since indus-
trial plants must be located near a large source of labor, a
proportionally larger fraction of plants must be found in
urban areas. As a reasonable estimate, it is assumed that 80%
of all industrial plants are located in urban areas. It is
further assumed that these urban areas have an average urban
population density of 50C0 people per square mile.
G.6 Noise Exposure Estimates
To estimate the noise exposure as a function of distance from
industrial plants, we first find the average horsepower used
by each plant. The number of operating minutes is taken over
one year:
60 (min/hr) x 2^ (hr/day) x 6 (day/wk)
x 52 (wk) = M.iig x 105 (min). (0.2}
In 1977, United States industry purchased 2.307 x 10-5 3TU
of electrical energy [G-5]. It is assumed that two-thirds of
this energy drives noise producing machinery, giving a total
noise-related horsepower per year of:
G-7
-------
Hp = 3TU f mln x hp/HTU/mln
= 2.307 x 1015 (ET'J) x 2/3
*(4.49 x 105 (mln)) x .02356 (hp/BTU/min) (G.3)
= 8.07 x 107 (hp)
where .02356 is the conversion factor from BTU-mln to hp.
The sound power level emitted by each plant Is given by (from
Eq. G.l)
?WL =88+10 log (8.07 x 107 (hp/yr)
+ 3.207 x 105 (plants))
= 112.0 d3 . (G.4)
The sound pressure level L at a distance d (in feet) from a
noise source with a sound power level of PWL is given by Ref.
G-6:
L = PWL - 20 log(d) - 0.6 + C, dB, (G.5)
where C is a temperature/pressure correction term with a range
of about _+ 0.5 dE over typical temperatures and pressures. In
this formulation, the 20 log(d) term indicates an assumed
attenuation rate over distance of 6 dB per doubling of dis-
tance. Ey ignoring the third and fourth terms of Eq. G.5 and
substituting Eq. G.4, we have:
L * 112 - 20 log(d), dB. (G.5)
It has been observed that in a typical industry situation the
hourly usage of electrical energy during nighttime hours is
about twc-thlrds of the use during daytime hours. The L^n
resulting from this usage pattern is then:
^dn - 10 log X [15 x 10L/1C + | x 9 x 10(L+10^/10]
* L + 10 log (.7 5/2 4)
s L r 5, dB. (0.7)
G-8
-------
Substituting Eq. G.6 and subtracting .6 dB to account for
shielding within the community results in a final equation for
the community noise levels around Industrial plants of:
Ldn - 111 - 20 log(d). (G.8)
Assuming the minimum noise reduction of 15 dB found in
residential buildings (see ref. G-7) applies to industrial
sources inside the plant, it can be reasoned that these
Interior sources do not contribute to the noise exposure. We
also assume that there are no residents within 150 ft of the
plant.
The distances for various L^n values are easily determined
from Eq. G.8. We compute the area around t:ie plant
corresponding to a given Ldn and multiply 'r 1) 260,000
plants in urban areas, 2) 50* to account for external sources
only, 3) a population density of 5000 people per square mile,
and 4) 25£ to account for noise radiated toward residential
areas. The result is the number cf people actually exposed
nationwide to this particular L
-------
The population exposed to an Ldn of 60 dB or higher from
industrial ncise is therefore:
0.0117 x 260,000 x 0.5 X 5000 x 0.25 = 1.9 million. (G.10)
Similar calculations result in the distribution of people vs
Ldn contained in Table G.2.
TABLE G.2. U.S. POPULATION EXPOSED TO VARIOUS
LEVELS OF Ldn OR HIGHER FROM INDUSTRIAL NOISE.
hdnim
Number (In Millions) of People
>65
>60
>55
0.3
1.9
6.9
-------
REFERENCES FOR APPENDIX G
G-l Administrator of the U.S. Environmental Protection
Agency, "Report to the President and Congress on Noise,"
in compliance with Title IV of Public Law 51-604, The
Clean Air Act Amendments of 1970, Senate Document 92-63,
U.S. Government Printing Office, February 1972.
G-2 I. Dyer and L. Miller, "Cooling Tower Noise," Noise
Control, May 1959-
G-3 J.B. Graham, "Fan Selection and Installation," ASHRAZ
Symposium paper June 1975, American Society of Heating,
Refrigeration, and Air Conditioning Engineers, Inc., 3^5
East 4 7 th Street, New York, NY 1C017.
G-4 L. Miller, Lecture notes for course "Noise Control
Techniques for Industrial and Manufacturing Plants," Bolt
Eeranek and Newman Inc., 1979-
G-5 U.S. Department of Commerce, Bureau of the Census, "Sta-
tistical Abstract of the United States: 1979," 100th
Edition, Sept. 1979-
G-c Cyril M. Harris, ''Sound and Sound Levels," in Handbook
of Nclse Control (C.M. Harris, ed.), 2d edition, McGraw-
Hill Book Co., New York, 1979.
C—7 U. S. Environmental Protection Agency, "Information on
Levels of Environmental Noise Requisite to Protect Public
Health and Welfare with an Adequate Margin of Safety,"
Report No. 550/9-74-00^, March 1974.
-------
-------
APPENDIX H. AGRICULTURAL NOISE EXPOSURE IN THE COMMUNITY
H.l Noise Exposure Model
Recognizing differences in farm size, population distribution,
and character of farming operations, analyses were undertaken
for four regions of the country. These regions were chosen to
match the breakdown for which the most complete data were
available from the "Statistical Abstract" [H-l and H-2],
Table H.l lists the number of different mechanical equipment, ,
the resident population, and the density of farm population
for each region. In each case, the latest data available were
used, so the values cited in Table H.l represent different
years, as indicated. It should be noted that the number of
people on farms has decreased from the 197C figure given in
the table to the 1978 figure of 8,005,000, and the total num-
ber of tractors has decreased to ^,370,000 [H-2] for 1578.
H.2 Noise Sources
The principal noise source on the farm is the tractor. The
truck is quieter, mors likely to be operated on roads (where
it becomes part of the traffic population considered in Appen-
dix C), and the combine and corn picker operate only for a
short time curing the harvest season.
Reference H-3 contains data on noise levels emitted by trac-
tors. From these da~a, the A-weighted sound level of tractors
at full power measured at 5C ft is
-------
TABLE H.l. 1'ARM RB3I0N DATA.
No. of No. of
Tractors Trucks
Region (xlOOO) (xlOOO)
No. of
Combines
(xlOOO)
No. of Farm
Corn Pickers Population
(xlOOO) (xlOOO)
Population
Total Area Density
People/
(Sq.ml.x 103) Sq. Ml.
Northeast 311
North
Central
South
West
'IOTAI.
2316
130L
507
'I'168
158
1335
1065
180
3038
11
351
106
50
521
33
181
91
9
611
699
1305
3751
951
9712
11
580
506
511
1611
17
7-1
7.1
1.9
5.9
Phte of
l>ita 1971 1971 1971 1971 1970 1979
Reference ll-l H-l 11-1 H-l H-2 H-2
-------
LA = 62 + 10 log (hp)j
(H.l)
where is the "A-weighted" sound level In decibels. It
must be noted that variations of up to +10 dB can be observed
for particular tractors. In calculating noise exposure, ini-
tially only the sounds of tractors will be considered. The
typical (average) tractor is of 5^ hp, on the basis of refer-
ence H-2 for the total number of tractors in 1978 (4.370 x
lQ^), and the total horsepower of tractors (238 x 10^ hp).
Therefore, from Eq. H.l, a tractor with 5^ hp could be expected
to generate the following levels during full power operations
and during engine idle operations (assumed to be at 50%
power):
LA = 62 + 10 log (54) =¦ 79 dB full power (H.2)
LA = 62 + 10 log (5*0 + 10 log(0.5) 3 76 dB idle. (H.3)
Reference H-2 indicates that full power operations Involve
roughly 600 hours per year per tractor and idle operations
Involve about 200 hours per year.
Assuming that all of this activity takes place during daytime
hours and noting that there are 5,^75 daytime hours per year
(between 7 a.m. and 10 p.m.)j the average annual Leq at 50
ft during the daytime for an average tractor at full power is
~hen:
Lsq = 79 + ID log '¦ 547 5^day-hr/yr)
= 69 dB,
(H.4)
-------
and at idle is;
T - ?<; 4. 1 r 200(hr) N
Leq - 76 + xO log (5475 (day-.hr/yr)'
= 62 dB. (H.5)
The average annual Ldn at 50 feet is then:
1 69/10 62/10
Ldn - 10 log (15 x(10 +10 ) + 9 x 0)
» 68 dB. (H.6)
Since the Ldn(R) at a given distance R from the tractor
is
Ldn(R) = Ldn(50 ft) + 20 log 50/R, d3, CH.7)
we can derive the distance at which a given Ldn occurs, as
follows:
R = 50 x 10(63~Ldn)/2° .
(H.8)
?or example, the radius at Ldn = 65 dB is
a ¦ 50 x io;b°-6")/i:C =
(H . 9 )
'The radii ana impacted area values obtained in this way for
^dn 55, 60, and 65 are shewn in Table H.2.
H-4
-------
TABLE H.2. IMPACT OP AVERAGE TRACTOR.
Annual Area of
I<£n Radius Impacted Area
(dB) (ft) (sq miles)
>65 71 0.00056
60 - 65 126 - 71 0.00122
55 - 60 223 - 126 0.003S3
H-5
-------
H.3 Noise Exposure Estimates
The number of people In each region of the country exposed to
various levels of noise is estimated in the following way.
First, the number of tractors in each region is multiplied by
the Impact areas calculated in Table H.2. Then these values
are multiplied by the appropriate regional population densi-
ties. For example, the area impacted by 65 dB L,jn or
greater in the Northeast is:
314,000 tractors x O.OOO56 sq miles/tractor=176 sq mi, (H.10)
and the population Impacted is:
176 sq miles x 17 people/sq niles=2992 people. (H.ll)
Finally, two adjustments are made that account for the assump-
tions that 1) tractors are operated in areas around the farm
that have less than the average population density, and 2)
machinery other than :rac:ors add to the noise exposure. To
obtain the first adjustment we can assume that the population
on a farm is geometrically distributed over the farm area.
That is, half of the area has the average population density,
one-fourth of the area has one-fourth the population density,
and so on. For instance, if the tractor operates primarily in
a low-density environment and the area above Ldn 55 d3
from tractor noise is 1/20 of the total farm area, we assume
the actual population density within the 55 dB contour is 1/20
cf the average. Another way to view this adjustment is to
assume that all the people on the farm are packed into an area
the size of the 55-dB contour. Then, if the tractor spends
equal time in each part of the farm, the average impacted
-------
population will be the average population density times the
ratio of the contour area divided by the farm area.
To obtain the second adjustment, we assume that 50? of farm
trucks and 100? of combines and corn pickers impact the farm
population In the same way and az the same noise levels that
tractors do. Prom Table H.l, this assumption results in a 40
to 64? Increase In "equivalent" tractors, depending on the
region. For simplicity, the second adjustment Is assumed to
be a 50? increase in the final adjusted values for all
regions. The adjusted exposed population 13 shown In Table
H.3.
Table H.4 summarizes the national distribution of people
exposed to various levels of Ldn from agricultural
machinery. These values might oe further increased because
over 45? of the workers in agrJ cultural work live off the
farm. Correspondingly, they might also be decreased because
49? of the employed persons living on farms work in urban
areas at other than agricultural work and so are away from the
farm during the cay [H-5j-
-------
TABLE II.3. ESTIMATED NUMBER OP PEOPLE EXPOSED TO VARIOUS LEVELS
OF Ltfp OR HIGHfR FROM AGRICULTURAL NOISE.
Population Density
Annual Ldn
Area Impacted
x Area Impacted
Adjustment
Adjusted Number of
Region
(dB)
(sq miles)
(persons)
Factor*
Persons Exposed
Northeast
>65
176
2992
0.061
191
60-65
383
6511
0.061
117
55-60
1203
20151
0.061
1309
North Central
>65
131'l
9723
0.031
331
60-65
2862
21179
0.031
720
55-60
8985
66*489
0.031
2261
South
>65
729
5395
0.022
119
60-65
1587
11711
0.022
258
55-60
1983
368/1
0.022
811
West
>65
28'l
510
0.008
\
1
60-65
619
1176
0.008
9
55-60
1912
3690
0.008
30
U.S. (Tbtal)
>65
2503
18650
615
60-65
5'I51
'10610
1101
55-60
17113
127501
1181
* Obtained by dividing the area Impacted above 55 dB (the sun of the 55-60, 60-65, arid >65 dB bands) by
the total area In each farm region shown in liable II.1, and nultiplying by 1.5 to account for the notse
from other machinery.
-------
TABLE H.4. U.S. POPULATION EXPOSED TO VARIOUS
LEVELS OP Ldn OR HIGHER PROM
AGRICULTURAL NOISE.
Lnn CdB) Number of People
>65 645
>60 2049
>55 6460
K-9
-------
REFERENCES FOR APPENDIX H
K-l U.S. Department of Commerce, Bureau of the Census, "Sta-
tistical Abstract of the United States: 1977," 98th
Annual Edition, September 1377.
H-2 U.S. Department of Commerce, Bureau of the Census, "Sta-
tistical Abstract of the United States: 1979." 100th
Annual Edition, September 1979-
H-3 University of Nebraska - Lincoln, Department of Agricul-
tural Engineering, "Nebraska Tractor Test Data 1977,''
February 1977.
H-^l Southwest Research Institute, "A Study of Noise Induced
Hearing Damage Risk for Operators of Farm anc Construc-
tion Equipment," U.S. Department of Commerce/National
Bureau of Standards, Report No. ?B ltid-633, December
1969-
H-5 U.S. Department of Commerce, Bureau of the Census, U.S.
Department of Agriculture, Economic Research Service,
"Farm Population of the United States, 1976," Series
Census-ERS, p.27, No. ^9, December 1977.
H-10
-------
APPENDIX I. BUILDING MECHANICAL EQUIPMENT NOISE EXPOSURE IN
THE COMMUNITY AND IN BUILDINGS
1.1 Noise Exposure In Buildings
1.1.1 Noise sources
The noise of building mechanical equipment should not normally
provide any Impact, if designed and Installed correctly. The
data in ref. 1-1 list typical building mechanical equipment
and the sound level 3 ft from the source and also the esti-
mated sound level at the nearest occupant's position. The
latter figure is derived by Including a calculated reduction
for the structure and acoustic treatment between the source
and the nearest building occupant. These results, included
here in Fig. 1-1, show that only the emergency diesel genera-
tor produces A-weighted sound levels of greater than 45 dB.
Since these machines only run intermittently (e.g., 1 hour per
week for testing purposes), this analysis indicates that there
is relatively little acoustic Impact from building mechanical
equipment for occupants inside buildings.
1.1.2 Noise exposure estimates
In practice, building mechanical equipment is not always pro-
perly installed, anc full acoustic- treatment is not applied.
Experience suggests that the noise of central air conditioning
systems, elevator mechanisms, and boiler forced-craft fans
commonly produce A-welghted sound levels greater than 45 dB in
occupied spaces.
-------
FIG. 1.1. RANGE OF BUILDING EQUIPMENT NOISE LEVELS TO WHICH
PEOPLE ARE EXPOSED [i-l].
A-WEIGHTED NOlSf LEVEL
30 40 SO 60 70 80 CO 100 110 170
LAMP BALLASTS
ANO VAPOR
OtFFUSERS
MIXING BOXES
FAN COIL
TRANSFORMERS
PUMPS
BOILERS
STEAM VALVES
CHILLERS
ELEVATORS
AIR COMPRESSORS
COOLING TOWERS
FANS
DIESEL EMERGENCY
GENERATOR
• NOISE LEVEL AT 3 FT FROM SOUnCE
O NOISE LEVEL AT OCCUPANT'S POSITION
1-2
W- I.VTEm-ENtMfi WALL
0- OUCT TREATMENT
E - ENCLOSURE OF SOUIP.
R - INTERVENING ROOF
STRL'CTL'^E
S - OUFFER ZONE FLOOR
BETWEEN SOURCE ANO
OCCUPANT'S FLOOR
V - VIBRATION ISOLATION
OF EQUIPMENT
-W ~ V-
-W ~ V-
-W+ V-
-W* V-
¦ W
• W + V-
-S ~ fl * V-
•W ~ D ~ V-
•W ~ V-
-------
There are many office buildings, hospitals, stores, hotels,
and convention centers where the noise of the air conditioning
system can be expected to generate similar levels, but any
estimate would be speculative at this time.
1.2 Noise Exposure In the Community
1.2.1 Noise sources
The exterior noise produced by building mechanical equipment
is most probably dominated by air-moving equipment (fans)
located outside the building or located inside the building
with a direct unmuffled path to the outside. Examples of such
fan-related equipment Include air conditioners, boilers, con-
densers, cooling towers, dehumidifiers, furnaces, humidifiers,
and ventilators.
Source level and operating information is available. For
example, cooling towers will typically produce A-welghted
sound levels of 65 dB at 200 ft when operating at full speed.
Axial exhaust fans can produce A-welghted sound levels of 61
dB at 200 ft from the exhaust vent [1-1 to 1-4].
1.2.2 Noise exposure estimates
No information is available at this time on the distribution
of the population relative to building mechanical equipment to
provide a direct estimate of impact. However, it has been
observed that building mechanical equipment contributes to the
-------
noise environment in built-up areas, and also that community
complaints about building mechanical equipment noise are often
concerned with nighttime disturbance, when traffic and other
noise is minimized. In addition, a poor choice of location,
such as one allowing residential buildings to overlook cooling
towers, can cause real problems. In a study that considered
one such "noisy plan" in a hypothetical apartment unit, noise
from building equipment assumed to be on a neighboring roof
was the main exterior noise source, producing an of 50
dB inside the unit [1-5]- Next in importance was noise from
an adjacent trash chute and elevator system, producing Ml dB
Inside the unit.
1.3 Concluding Remarks
Building mechanical equipment is probably not a major source
of acoustic impacts. However, a noise problem can result from
poor design and/or incorrect installation. In this case, the
continuous nature of the noise produced can result in very
serious local problems. Disturbance to sleep and Interference
with activities that require concentration probably represent
the principal effects. However, insufficient data are
presently available to quantify the extent of this problem.
1-4
-------
REFERENCES FOR APPENDIX I
1-1 I. Dyer and L. Miller, "Cooling Tower Noise," Noise
Control. May 1959.
1-2 ASHRAE Guide and Data Book, 1963, Chapter 14; 1967,
Chapter 31; American Society of Heating, Refrigeration
and Air Conditioning Engineers Inc., 345 E. 47th Street,
New York, NY, 10017.
1-3 G.A. Campano and W.E. Bradley, "Radiation of Noise from
Large Natural Draft and Mechanical Draft Cooling Towers,"
Paper 74-WA/HT-55, presented at ASME Annual Meeting,
November 1974.
1-4 J.3. Graham, "Fan Selection and Installation," ASHRAE
Symposium Paper June 1975, American Society of Hearing,
Refrigeration and Air Conditioning Engineers, Inc., 345
E. 47th Street, New York, NY, 10017.
1-5 R.L. McKay, "Criteria for Interior Residential Noise,"
BEN Report 316S, for the U.S. Department cf Housing and
Urban Development, June 1976.
-------
APPENDIX J. HOME APPLIANCE, POWER SHOP TOOL, AND OUTDOOR
POWER EQUIPMENT NOISE EXPOSURE IN THE COMMUNITY
AND IN BUILDINGS, AND EXPOSURE OP OPERATORS
Tills section presents noise data and estimates of L
-------
J.2 Nol3e Exposure Model
The noise level results presented in Table J.l are taken from
a study of consumer product noise [J-l], and these results
derive from tests performed on consumer products In accordance
with ISO standards for testing of small noise sources. In
most cases, the noise levels represent an average of more than
one product operated under various normal operating condi-
tions. Since a proper nationwide consumer appliance noise
survey has not been performed at this time, the extent to
which these averages reflect the actual population of products
In use (with their varying degrees of degradation, operating
power, and other manufacturer-specific characteristics) Is not
known.
The measured sound power level (in d3 re 10-12 watts),
along with the average operator distance ana the average room
acoustical environment allow the calculation of an operator or
bystander exposure level. The combination of this exposure
level and the estimated yearly usage allow the calculation of
a 24 hour Leq. Because there are no data indicating the
portion of any product's use during nighttime hours between
2200 and 0700 hours—thereby incurring the 10-dB penalty—the
value for Leq (2*0 will be assumed to be equal to the
value of I^dn* This assumption nay not be too far from
reality when one considers that most of these sources are
under direct operator control, and common courtesy and normal
usage patterns will tend to preclude use during the hours when
most people sleep.
Estimates of product ownership come from three different
sources. Wherever possible, data from a survey reported in
the April 1978 Issue of Appliance Manufacturer were used to
estimate the percent of households that own a given consumer
J-2
-------
TABLE J.l. SOISE FROM CONSUMER PRODUCTS.
Product
Sound Pomp
Lave)
(«;'
Operator
DllUnee
(ft)
Room
Acoustic
Constant
mag*
(hrs/wk)
0«ner*h1 p
(I)
Operator
Sound Ltvtl
(dBj
Op«rator
L« <24'
Papulation
Eipoitd
to L fri »«5
(Ml flam)
Paelal Bruah
63.5
0.23
33
0.125
3
74.9
43.6
0.0
lair Clipper
61
0.25
33
0.124
12
72.4
41.1
0.0
lilr Dryir
SO
0.23
33
0.983
73
91.4
69.1
53.29
Sh«v«r
70
0.23
33
0.488
42
81.4
}«.l
30.66
Tooth Brush
63
0.23
33
0.700
6
74.4
30.6
4.38
Rlaadar
91
3.0
*3
0.063
66
90.9
56.6
48.18
Can Opener
69
3.0
«3
0.072
79
68.9
33.2
0.0
Co/ft* Crloder
10
3.0
43
0.019
12
79.9
40.4
0.0
Food Mliir
73
3.3
43
0.187
91
74.9
43.4
66.43
Pood PTOC«MOr
92
3.0
43
0.0125
3
91.9
50.6
2.19
lea Cnuh«r
12
3.0
43
0.018
6
81.9
42.2
0.0
Juicer
78
3.0
43
0.065
6
77.9
43.8
0.0
Electric Knife
84
3.0
43
0.051
18
93.2
38.7
13.14
Calf* Sharpener
84
:.o
43
0.041
12
83.9
47.8
8.76
Dental Irrigator
75
:.o
35
0.166
15
76.3
46.:
1C.95
Maasager
a
2.0
173
0.0064
6
30. J
6.1
0.0
Pcodl Sharpener
79
'.0
173
0.146
6
74.0
43.4
0.0
Pet Clipper
62
'.0
43
' 0.0064
1
61.9
17.7
0.0
Electric Scliaore
74
. J.o
175
2.06
15
69.0
49.9
10.95
Scwlof Machine
81
3.0
175
1.28
84
76.0
34.8
61.32
1 Shorn Poilehes
75
3.0
173
0.123
3
70.0
38.7
0.0
J Floor Pollaher
74
6.3
43
0.077
1
73.6
40.2
0.0
Bug Shaspooer
94
6.0
173
0.077
47
88.0
54.6
34.31
Vacua Cliaar
91
6.0
173
1.309
93
85.0
63.9
69.35
Cloc&ee Dryer
73
10.0
43
5.8
58
72.3
37.9
42.34
73
10.0
43
3.93
72
74.5
58.2
52.56
Debumijilfier
61
10.0
43
12.93
18
60.5
49.4
39. *
Dlehvaaher
67
10.0
45
3.435
48
64.5
49.6
35.04
Food Uuti Dlffp.
82
3.0
45
0.331
40
81.9
55.1
29.2
laa^ • Bood
68
2. z
45
1.744
43
67.9
49.1
31.39
Re/rlgeraeor
34
10.0
45
42.0
94
53.5
47.5
68.(2
ftoaa Air Coed.
67.6
10.0
175
8.318
36
61.3
48.3
75.5
Traeh Caapactor
74
10.0
43
0.23
4
73.5
45.3
2-92
Air fteatar
37
10.0
175
3.208
6
50. 7
21.7
0
Fan
70
10.0
173
16.408
54
63.7
53.6
US.3
Hunldl/ler
38
10. 0
175
71.09
21
51.7
43.3
U6.C
lea Cren Machloe
73
10.0
45
0.058
1
74.5
39.9
0
Movie Projector
69
10.0
173
0.02
6
62.7
23.3
0
Slide Projector
66
10.0
173
0.067
40
59.7
23.7
0
Band Saw
90.3
3.0
0.2
1
90. t*
61.2
0.73
Bale Sander
102
3.0
45
0.047
12
101.9
66.4
a.76
Icaeh Crlndar
84
3.0
45
0.143
9
93.9
33.2
6.73
Circular Saw
103
3.0
0.144
21
102.9
72.2
15. J3
Diet Sender
100
3.0
45
0.027
6
99.9
62.0 :
4.3B
Drill lit Sharp.
88
3.0
43
0.0064
3
87.9
43.7
0
J-3
-------
TABLE J.l. NOISE ?ROH CONSUMER PRODUCTS (CONTINUED).
Product
Sound Power
Level
(da )
Operator
Distinct
(ft)
Room
Acoustic
Constant
Usage
(hrs/xk)
0wn«rin1p
(X)
Operator
Sound Level
(dB )
Operator
Le, <">
Population
Exposed
« L9n >
-------
product [J-2]. Where no data existed, data from a 1980 survey
specifically tailored to obtain noise exposure information
were used [J-l]. A third study published in the March 1977
issue of Merchandizing was used for comparison [J-3]. The
values obtained for each of these surveys differ somewhat due
to differences in sample population, sample size, survey date,
and survey methodology, but they represent best estimates at
the present time.
Usage estimates are also not known with a high degree of
accuracy, in light of the extremely varied situations and
patterns of usage of individual products in different regions
of the country.
For the purpose of this analysis, there are assumed to be two
bystanders for products requiring an operator, three for pro-
ducts requiring no operator, and six for products used out-
side. Based on 1578 Statistical Abstract data, there are
approximately 73 million households in the United States.
J.3 Noise Exposure Estimates
As is apparent from reviewing the results shown in Table J.l,
a large number of products produce Ljn levels in excess cf
the ^5-dB criterion level. However, since these products do
not generate levels of sufficient intensity to have an impact
on people other than the operator, the number of exposed peo-
ple is the number of product owners. For certain indoor pro-
ducts without operators (humidifiers, dehur.ldifiers, fans, and
air conditioners), the number of exposed people is based on
three people exposed per household. It is also interesting to
note that some power shop tools produce levels sufficient to
exceed the LSq (24) level of 70 d3 for the operator expo-
sure.
-------
These results Indicate that a significant noise exposure can
occur in the typical home environment particularly if one is
engaged in a hobby that uses a product that produces high
noise levels. These exposures, while not necessarily harmful
in themselves, can be significant for that portion of the
population already exposed to the maximum daily noise dose in
the workplace. The lack of more precise data on the number of
product users and use durations precludes an accurate estimate
of nationwide exposure to home products at this time.
j-6
-------
REFERENCES FOR APPENDIX J
J-l "Consumer Product Noise," BBN Report No. 43^1 (Draft
Final), March 1980.
J-2 Appliance Manufacturers, April 1978.
J-3 Merchandizing, March 1977-
-------
APPENDIX K. OCCUPATIONAL NOISE EXPOSURE OP WORKERS
The U.S. Environmental Protection Agency (EPA) has recommended
an equivalent sound level for eight hours [Leq (8 hr)] of
75 dB as the exposure level to protect workers from permanent
hearing loss [X.l]. Many workers in agriculture, mining,
construction, manufacturing, transportation, and the military
are routinely exposed to levels in excess of this recommenda-
tion. The legal limits Imposed by the Occupational Safety and
Health Administration (OSHA) [K.2,K.3], the Mining Health and
Safety Administration (MSHA) [K.U], and the Department of
Defense (DOD) [X.5] are less restrictive than the EPA-
recommended level.
No concrete estimates exist of the number of workers exposed
to noise levels greater than an Lec (8 -n-") of 75 dB.
There is, however, a United amount of published information
on the occupational noise exposure of workers in some occupa-
tional categories In selected industries. Even though these
data were developed for different purposes, it has been possi-
ble to develop estimates of the minimum number of workers ex-
posed to levels greater than an Lec (8 hr) of 8 5 d3
through the use of extensive extrapolations. These estimates
are presented in the sections that follow. Brief explanations
of the extrapolation techniques and the source data are also
presented in the following sections.
In addition to their exposure to continuous noise, many
workers are exposed to impact/impulsive noise. This type of
-------
noise can greatly Increase the amount of hearing loss due to
either continuous or inpact noise. Recommendations for
criteria for exposure to impact/impulsive noise alone and
together with high-level continuous r.oise are under develop-
ment. Preliminary estimates indicate that 1 million to k
million workers are routinely exposed to high levels of
impact/impulsive noise. Additional details are presented
later in this appendix.
As is the case with any estimate, the estimates in this
appendix are somewhat limited. The principal difficulty in
estimating the occupational noise exposure of the total U.S.
work force is in obtaining r.oise exposure data for a repre-
sentative population for each of the employment categories and
industries analyzed. The current assessment was restricted to
available data and no additional sampling or measurements were in-
cluded. It should be noted thai the available data are often lacking
the representativeness of an industry-wide assessment.
X.l Noise Exposure in the Agriculture Industry
A nunber of studies confirm that agricultural workers who
operate tractors and other mechanized farm equipment are ex-
posed to A-weighted sound levels greater than 85 d3 and that
the duration of the noise is sufficiently long that NIPT3 nay
result [K.b, K.7, K.8, K.S, K.1Q, K.ll]. The most complete
set of ncise exposure measurements was made in 1977 for a
group of farm workers on six farms in Nebraska [K.12J. Each
worker was fitted with a ncise dosimeter for each cay worked.
During the course of one year, 67 employees worked the
-------
equivalent of 13,000 days. From these data, it was possible to
estimate the average noise exposure of each worker for the
year.
To develop an estimate of the noise exposure of all the agri-
cultural workers from these data, two facts must be con-
sidered- First, the noise emitted by farm tractors has been
reduced in recent years [X.8, K.9]- The manufacturers of the
tractors used on the Nebraska study farms have reduced the
noise of their tractors during the past few years by an aver-
age of 2 dB. Accordingly, If the Nebraska farm survey were
done today, the workers operating those tractors would be ex-
posed to less noise. This effect has been estimated by reduc-
ing the noise exposures of each of the 67 workers by 2 d3 and
recalculating their noise exposure. Table K.l summarizes the
Daily Noise Dose (DftD) for each of the workers, what the dose
would be if the ncise were 2 dB quieter, and the corresponding
range of r.oise levels.
Second, the six farns in this study seen to be more mechanized
than "typical" farms. Without any information to relate the
mechanization of each of these farms to a typical farm, it is
not possible to develop ar. estimate of the noise exposures for
all agricultural workers. An educated guess is necessary:
For every situation where workers are exposed as reported in
this study, an equal number of workers on ether farms have
exposures less than 7C d5. Table K.2 summarizes the exposures
from Table K.l, adds in the equal number of workers exposed to
levels less than 70 dB and presents the percentage for each
range.
-------
TABLE K.I. NEBRASKA FARM WORKER EXPOSURE DATA [K.I]
OSHA
Range of Noise
OSHA
Range of Noise
DND if
Level If
DND if
Level If
Equipment
Equipment
Equipment
Equipment
OSHA
2 dB
2 dB
OSHA
2 dB
2 dB
DND
Quieter
Quieter
DND,
Quieter
Quieter |
Fara %
X
dB
Farm
%
%
dB
/a 93
58
85-90
92
53
33
80-85
38
24
75-80
24
15
75-80
61
38
80-85
13
8
70-75
18
11
70-75
33
20
75-80
3
2
<70
288
181
90-95
142
90
90-95
60
38
80-85
71
45
80-85
33
21
75-80
113
27
17
75-80
8
5
<70
1
1
<70
120
76
85-90
14.
9
70-75
6
4
<70
27
17
75-80
97
61
85-90
1
1
<70
18
11
70-75
1
1
<70
0
0
<70
7
4
<70
0
G
<70
7 •
4
<70
c
0
<70
9
6
<70
5
3
<70
21
13
75-80
40
25
80-85
13
8
70-75
10
6
<70
6
4
<70
it 4
I
4
<70
8
5
<70
17
11
70-75
117
74
85-90
26
16
75-80
j 105
66
85-90
7
4
<70
4
3
<70
5
3
<70
it 5
83
52
85-90
! 55
35
80-85
35
22
7 5-80
162
102
90-95
178
112
90-95
#6
27
•? ^
1 /
75-80
97
61
85-90
13
3
70-75
i 72
45
80-85
J
L
<70
52
33
80-85
3
i.
<70
1 115
73
85-9C
3
n
<70
38 24 75-80
4 3 <70
11 7 70-75
29 18 75-80
6 4 <70
41 26 80-85
10 6 <70
-------
TABLE K.2.
DEVELOPMENT OF EXPOSURE ESTIMATES FOR AGRICULTURAL WORKERS
Range of Sound
Level in dB
Number of
Workers
Equal Number
Exposed Co
Less Than 70 dB
Totals
%
<70
26
67
93
69.3
70-75
8
8
6.0
75-80
12
12
9.0
80-85
9
9
6.7
85-90
8
8
6.0
90-95
4
4
3.0
Totals
67
67
134
100
Approximately 2•6 million workers are employed in agriculture
[K. 13] • 'The percentages in Table K.2 have been used to
develop estimates of the noise exposures of agricultural
workers. These estimates are presented in Table X.3. Of the
3-6 million agricultural workers, about 323,000 are exposed tc
an Leq (8 hr) of 85 dB or greater.
TABLE K.3. NOISE EXPOSURE OF AGRICULTURAL WORKERS.
LM (8 hr)
(dB)
Number of Workers
(thousands)
90 - 94
108
cr>
00
1
in
00
215
00
0
1
00
240
75 - 79
323
<75
2701
-------
K.2 Noise Exposure In the Mining Industry
The raining industry consists of the extraction of coal,
metals, nonmetallic minerals, and oil and gas from the earth
and the preparation of these materials. Noise exposure data
in this industry are extremely limited. No noise exposure
data are available for the preparation of the nir.ed materials.
Data are available for the underground and surface mining of
coal. The estimates in this section are based on extrapola-
tions from the mining of coal.
Where the data permit, the Leq (3 hr) exposures have been
calculated and will be presented. Data examined were limited
to workers exposed to daily noise levels in excess of that
allowed by noise exposure regulations of the Federal Coal Mine
Health and Safety Act of 1969- However, most of these data
are reported as Lmsha values, which are oased on a
5-d3 doubling rule rather than the 3-dB ioubling rule used in
deriving an Leq measure. If the sound exposures are
continuous at a constant level, both the Lsa and
^MSHA values would be equal. However, industrial
sounds vary considerably, and with a varying sound level, the
value of Lec will be greater than the value of
Lmsha• Thus, the reported numbers of workers exposed
to values of are less than would have been
reported if Leq calculated exposures had been utilized.
For these reasons—lack of data generally available on noise
exposures in the mining industry and the units in which the
mining exposures were reported—the estimates presented in
this section should be regarded as preliminary and probably
representative of the minimum number of workers exposed.
K-6
-------
Coal Mining
Underground
Data are available from MSHA on the noi3e exposure of under-
ground coal miners [X.l*4], based upon the results of a survey
of 2632 production workers in 12 underground coal mines. The
exposure estimates in this report were developed from specific
sound level and operating duration measurements for the
equipment commonly encountered, rather than from individually
measured worker exposures. Table K.4 presents the reported
percent of workers exposed to different ranges of noise
exposure. Estimates of the number of workers in underground
mining exposed to noise were then developed by multiplying the
percentages shown in Table X.4 by the 169,535 miners who
worked in deep coal mines in 1979 "K.15]. The first row of
Table K.7 (which appears later in this appendix) presents
these estimates.
TABLE K.4 NOISE EXPOSURE FOR UNDERGROUND COAL MINE WORKERS.
•"MSHA*
dB
Percent of
Workers Exposedt
*
>90
85 - 89
<85**
7.2
14.7
78.:
* Uses a 3-d3 doubling race.
t In view sf the aacerial in Ref. K.I6, these estimates appear low.
"Exact lower liiits below 35 dB are not precisely known.
Surface
The noise exposure estimates for workers in surface coal mines
were developed using the results of a noise exposure survey of
-------
operators cf mobile machines [K.17]. The related report pre-
sented the number of workers with exposures greater than 85 dB
and 90 dB and the total number in the survey. 'The number and
percentage of workers exposed to various equivalent sound
levels is presented in Table K.5« An estimate of the number
of surface miners exposed to the ranges of equivalent sound
levels shown in Table K.5 was developed by multiplying the
percentages shown in Table K.5 by the number of workers in
surface mines—82,147 [X.15 ] • These figures are presented
later in this Appendix in the second row of Table X.7.
TABLE K.5. NOISE EXPOSURE FOR SURFACE COAL fCLNERS.
SlSHA*
Nunber of
Percanc of
Coal Miners
dB
Coal Miners4'
(S)
>90
25,225
9
85 - 39
12.038
21.4
<85**
18,963
33.7
* Uses a 5-dB doubling ract. |
t See 3ef. K.17.
**Exacc lower linlLS below 95 dfl are not precisely
knovn.
Metal and nonmetallic mineral mines
r
Underground
As with coal mining, the noise exposures for underground
operations in metal and nonmetallic mineral mines are
different from those for surface mining. No studies are
available identifying the specific noise exposures of workers
in this type of mining.. However, an estimate has been
developed cf the percentage of workers in such underground
mines who are exposed to varying r.cise level ranges through
the use of information in Ref. X.18. The related report
X-8
-------
reviews the contribution of noise fron dies el-powered
underground mining equipment in the extraction of molybdenum,
uranium, potash, iron, coal, and salt. The report presents
information on diesel equipment sound levels, equipment
population, and typical duty cycles.
With this information an estimate can be made of the number of
noise exposed workers and their equivalent sound level
exposures. Table K.6 presents the estimated exposures. In
1974, 37,000 workers were employed in underground metal and
nonmetallic mineral mines [K.18] (or an estimated 2^.3% of
total underground mines.) An estimate of the total number of
underground miners in this part of the Industry was developed
by applying the distribution from Table K.6 to 2^.3% of the
173,800 people who currently work underground in this industry
[K.19]. The third row .:,f Table K. 7 presents these estimates.
Other sources, such as rock drills, fans, and crushers, also
generate high levels of noise ar.d were not included in Ref.
X-18. Thus, this estin.Oe should be viewed as the minimum
number of workers so exjosed.
TABLE K.6. NOISE EXPOSURE FOR UNDERGROUND MINERS IN METAL AND
NONMETALLIC MINERAL MINES.
Leq (8 hr)
Percent of Workers
(dB)
(*)
_>90
17.6
85 - 89
11.1 j
<85
71.3
Surface
About 75.7? (131,567 workers) of the people employed by the
metal and nonmetallic mines work above ground (developed from
-------
K.18 and X. 20 and the previous section). No information is
available on the noise exposure of these workers. The surface
mining of metal and nonnetallic minerals is different from
surface coal mining. The differences are:
. A higher concentration of equipment exists in metal
than in coal
. Drills are percussive in metal and rotary in coal
. More blasting occurs in metal than in coal
. Other unidentified surface equipment may add to noise
exposure.
Most of these differences seem to increase the noise exposures
cf the workers. However, as stated above, no data substanti-
ate this statement. Without any other data, the noise expo-
sure for surface workers in metal and nonnetallic mineral
mines has been developed by using the percentages from surface
coal (see Table K.5). These estimates are presented in the
fourth row of Table X.7.
Oil and Gas Mining
There were 327,500 production workers in oil and gas extrac-
tion in 1979 [X. 19]. No information on noise exposure cf
these workers is available. Moise sources are likely to be
engines, compressors, and mobile equipment, "without any
better information, the percentage distribution data from
the last column in Table K.5 for surface coal mine operations
were used to develop estimates for this industry. The results
are shown in Table K.7.
K-iC
-------
Summary
Table K.7 presents the noise exposure of the workers in the
mining industry: Almost ^00,000 workers have noise exposures
that exceed 85 dB out of a total employment of 957,000 [K.19].
TABLE K.7. NOISE EXPOSURE IN THE MINING INDUSTRY.
Noise Level
(dB)
<85
85 - 90
>90
Total
Underground Coal*
132,446
24,929
12,210
169,585**
Surface Coal*
27,684
17,579
36,884
82,147**
Underground Meta^
and Nonmetallic'
30,112
4,688
7,433
42,233"'"+
Surface Mecal and
Nonnetallic*
52,495
25,524
53,548
131,567+t
Oil and Gas*
110,368
70,085
147,047
327,500fX
.
Totals for Mining
353,105
142,805
257,122
*Noise Level is
"'"Noise Level is L (8 hr) .
eq
**See Ref. K.15.
^See Ref. K.20.
-------
K.3 Noise Exposure in the Construction Industry
A number of studies confirm that workers in the construction
industry are exposed to high levels of noise [X.ll, X.21]. A
recent British study [X.22] presented values of Leq (8 hr)
for machine operators of construction equipment. Table K.8
summarizes these data. Ey assuming that these exposures are
similar to those in U.S. industry, an estimate cf the number
of construction workers whose exposure exceeds an Leq (8
hr) of 85 dB can be developed. Reference X.23 presents the
number cf workers in the construction industry by occupation.
Accordingly Table X.9 was developed presenting the percentage
of workers in the construction industry who work with the
specific machine types listed in Table X.8. Unfortunately,
Reference X.23 does not provide the number of operators for
several of the machine types. Nevertheless, from Table X.9,
at least 5-^S% of the construction workers appear to operate
machines where the Leq (8 hr) exceeds 85 dB. In addition
to the machine operators, construction laborers are also
exposed to noise. About 11.353 of the construction work fore
are laborers [X.23j• The laborer category includes workers
who are exposed to nigh levels of noise, such as from jack
hammers and other air- operated tools, as well as individuals
with less noise exposure [X. 2*4 ]. However, no definitive
estimates are available for noise exposure of the laborers.
without a definitive breakdown of the number cf workers in
each of the laborer categories, the number of laborers who
operate the noisy equipment types cannot be determined. A
review of the list of Jobs performed by laborers suggests tha
many of these workers could be exposed to high levels cf
noise. Without better information, it is estimated that 50:1
of the laborers are exposed to levels greater than an Lsq
X-12
-------
TABLE K.8. NOISE EXPOSURE OF CONSTRUCTION MACHINERY OPERATORS.*
Equivalent Sound Level
L (8 hr)
eq(dB)
Machine Types
105 - 109
Pneumatic breakers
100 - 104
Pavers
95 ~ 99
Scrapers
Dumpers
Bar benders
Hydraulic breakers
Pile drivers
(dlesel & pneumatic)
90 - 94
Dozers
Excavators
Cranes
Front loaders
Rollers
Poker vibrators
00
1
00
Backhoes
Saws
00
o
1
00
Concrete pumps
Pile drivers
(gravity bored)
75 - 79
Graders
Concrete mixers
Trucks
Pumps
Generator
Compressors
•Developed from Ref. K.22.
K-13
-------
TABLE K.9. PERCENTAGE OF CONSTRUCTION MACHINERY OPERATORS BY MACHINE TYPE*
AND NOISE LEVEL.'
Le„ (8 hr)
(dB)
Machine Types
Percent of Construction
Workers Operating
Machine Type
[%)
>85
Dozers
0.99
1
Excavators (include
pavers, scrapers, hydraulic
breakers, pile drivers,
front loaders, back hoes,
rollers, poker vibrators)
3.85
Saws
0.04
Cranes
0.60
Pneuoacic breakers
**
i
Dumpers
**
Bar benders
**
Total
5.48
*See Ref. K. 23.
*See Ref. K.22.
**Not listed separately.
-------
(8 hr) of 85 d3. Since about 11.35? cf the construction force
are laborers [K.23], a total of 11.162 [5.48 + 0.5 (11.35)]
could be exposed to levels greater than an Leq (8 hr) of 85
dB. Since there are other Jobs in the construction industry
that may be noisy and for which there is no definitive informa-
tion, this estimate is more likely an estimate of the minimum
number exposed to these levels than an estimate of the maximum
number.
Total employment in the construction industry for 1979 was
about 4.6 million people [K.19]; thus, about 513,000 workers
are estimated to be exposed to levels greater than an Leq
(8 hr) of 85 dB.
K.4 Noise Exposure in the Manufacturing and Utility Industries
Estimates of noise exposures of workers in the manufactu 'ing
ar.d utility industries are presented in this section. T.e high
noise level Industries of interest are listed ir. Table 2-.. 10
along with the number of production workers in each industry.
In addition to these industries, some exposure to high level
noise may occur in the instrument manufacturing (SIC 38} and
the miscellaneous manufacturing (SIC 39) industries. All of
these estimates are derived from the recently available OSHA
information "K.25, K.26].
Table X.ll presents the total estimated noise exposure for
workers in these industries [K.19". Since Lea (8 hr) is
equal to Lqsua only when "he noise exposure is constant
and since the noise levels in the industrial work place fluc-
tuate over a considerable range, these estimates should be
viewed as minimum estimates of the number of workers at an
Leq of the same value. Nevertheless, more than 5*1 million
K-15
-------
TABLE K.I 0. INDUSTRIES INCLUDED IN ANALYSIS.
Industry
SIC Code
Number of I
Production Workers !
(thousands)
Food
20
1,176.2 (
Tobacco
21
52.5
Textiles
22
777.0
Apparel
23
1,122.2
Lumber and Wood
26
646.3
Furniture and Fixtures
25
398.0
Paper
26
541.5
Printing and Publishing
27
702.2
1 Chemicals
28
636.9
| Petroleum and Coal
29
139.7
i Rubber and Plastics
30
601.1
,
| Leather
1
31
207.4
! Stone, Clay, and Glass
32
560.5
! Primary Metals
33
978.3
Fabricated Metals
34
1,305.9
Machinery Except Elec.
35
1,616.2
Electric Machinery
35
1,378.6
Transportation Equipment
37
1,404.2
Utilities
49
659. 3
i
j Total
j 14,904.0
1
*See Ref. K.19.
K-lc
-------
TABLE K.11. NOISE EXPOSURE OF WORKERS IN MANUFACTURING AND UTILITY INDUSTRIES.
Exposure Level
Percent Exposed"1"
1
(dB)
(%)
Number Exposed**
>100
2.87
427,745 j
95 - 99
5.47
815,249
90 - 94
10.98
1,636,459 i
85 - 89
15.06
2,244,542
80 - 84
18,74
2,793,010
<80
46.88
6,986,995
|
Total
100.00
14,904,000 j
^Includes SIC Codes 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
33, 34, 35, 36, 37, and 49. SIC's 38 and 39 of Che manufacturing sector
are noc included. Only SIC 49 of Transportation and Public Utilities is
included in this table.
*See Ref. K.25.
**Based on a total population of 14,904,000 [.%. IS"
-------
workers in these industries are exposed to levels in excess of
an Lp„ (8 hr) of 85 d3.
K.5 Noise Exposure in the Transportation Industry
This section presents estimates of the occupational exposure to
noise of operators of commercial aircraft, trucks, buses, rail
locomotives, and rapid transit cars. Even less data are avail-
able for these operators than are available in other indus-
tries. However, preliminary estimates have been developed
based on extrapolations from the available data. In general,
average noise levels at either the operator position or in a
location not too far from the operator position are available
:k.27, K.23, K.29, K.30, K.31, X.32, X.33, K.3^, K.35, X.36,
K.373. Data for the number of operators were available for
some modes of transportation bur had to be developed for other
modes [K.38, X.3 9, K.40, X.41, X.42, X.43]. The average dura-
tion cf exposure was estimated for each of the operators [K.4C,
K. 45, K. 46]. The Leq (S hr) was derived from the average
sound level, the estimated number of hours of annual exposure,
and a total of 18S0 hr in a year.
Table K.12 summarizes the estimates cf the A-weighted sound
level, the annual exposure, the Lsc (8 hr), and the popula-
tion exposed. The operators with exposures greater than'an
lea (S hr) of 85 aB are the truck drivers and the rnotcrmen
and conductors on rapid transit systems. Surprisingly, the
personnel in the locomotive cabs co not appear to be exposed to
levels greater than an LSq (8 hr; of 85 dE. In total,
about 1.93* million operators are exposed to levels greater
than Leq (8 hr) of 85 d3.
K-18
-------
TABLE K.12. TRANSPORTATION OCCUPATIONAL NOISE EXPOSURE ESTIMATES
Souice
Eat 1mated
A-Welglited
Sound Level
at Operator
Pus 11Ion
(dB)
Annual
Exposure
(Mr)
Cut 1mated
Leq (8 lir)
(d B)
PopulatIon
Exposed
A i vara ft
|K.27,K.'J8,K.4'i,l(.45,K.46]
Commercial* Jet
Cockpit Crew
Kl tfttit At tendunts
Comincrc 1 «i 1 * Propel Icr
Cockpit Crew
Might Attendants
80+
85| K. 2/ ]
95**
94(K. 271
900fK.44,K.46]
1260[K.451
900fK.44,K.46l
l2M)fK.45l
77
8)
92
92
36,987[K. 38]
52.56MK.38l
90tt
128tt
Ttucka (Medium anil Heavy)
|K. 2fl,K.29,K. 10, K.39|
90fK.30|
14105
89
1,923,000[K.39]
Hu: iisu
|K.2/,K.31,K.40]
City (commuter bus)
InLcrc 11 y
Sclioo 1
79| K . 27 1
74f K.31 |
84| K. 31 ]
188()f K. 40]
l/70fK.40l
440) K. 40]
79
74
78
143.000fK.40l
24,000| K. 40 j
442.00orK.40j
UuiliXHub
|K.32tK.11,K.14.K.1S,K.4l
k . ia 1
l.oroinot 1 vcS
78| K.32 1
IflflO
78
75.OOOfK.4l|
Rapid Transit
|K.27,K.'U>,K.37,K.4ll
Mniv>riWM» ami Condurtorn
8f>( K.27]
1970
Bh
II,OR3fK.43l
Certificated route air carriers only.
tEstimated from Ref. K.27. Pilots in Jet aircraft are farther from the engines, estimate
5 dB less noise in coc kplt.
**Estimated from Ref. K.27. Pilots are closer to noise source.
II Estimated from number of aircraft in Ref. K.38.
§The average work week in the transportation industry is 30.7 hours [K.39]. Estimate that
drivers spend 75% of time in truck.
-------
K.6 Noise Exposure in the Department of Defense
Air Force
Of the 807,000 military (567,000) and civilian (240,000) em-
ployees of the U.S. Air Force in 1980 [K.39], 13^,200 were
given annual audiograms in 1980 and are presumably exposed to
levels in excess of 85 dB [K.H7]. The details are as follows:
The Army included 1,107,000 military (757,000) and civilian
(350,000) employees in 1978 [K.39 3 - Measured noise exposures
for these personnel are unavailable at this time. Preliminary
figures suggest that about 500,000 personnel (^00,000 military
and 100,000 civilians) are routinely exposed to high sound
levels ir. excess of 85 aB [K.^8].
In 1978, the Navy included 1,028,000 military (717,000) and
civilian (311,000) employees [K.39]. Unfortunately, direct est!
mates of the noise exposure of Navy personnel are unavailable
CK. 49 J • Assuming "That Navy personnel are exposed tc noise
sources similar to those in the Army and Air Force, a preliminar
estimate can be developed. The weighted average percentage of
military personnel in the Army and Air Force exposed to levels
greater than an Leq {9 hr) of 35 ls (400,000 +
106 , 500)/(757 , 000 + 567,000) or 38.3*2. The weighted average
percentage of civilian personnel in the Army and Air Force
exposed to levels greater than an L9Q (g ^r) of 55 is
(100,000 + 27,700)/(35 0,000 + 240,000) or 21.55?. Using these
Number of Air Force Personnel
Classification Receiving Audiograms in 1S8C
Military personnel
Civilian personnel
Total
106,500
27.700
134,200
A rny
Navy
-------
percentage values for the Navy results In the following
estimates:
Military
Civilian
.333 x 717,000 = 271,611
.216 x 311,000 = .67,176.
Table K.13 summarizes the exposure of DOD personnel—about
976,000 personnel have estimated exposures greater than an
Leq (8 hr) of 85 dB.
In addition, 77,000 non-military employees of DOD are in
positions where occupational noise exposure cannot be assessed
K.7 Exposure to Impact/Impulsive Noise
Two studies present estimates of the r.unber of workers exposed
to impulsive type noise. One study, a walk-through survey of
25 establishments estimates that 2,665,687 workers are exposed
to impulsive noise [K.50]. The level and number of impulses
were not reported. The second study [K.51] identifies several
hundred sources of impulsive noi3e for a wide range of
industries. This study estimates that 1,200,000 workers are
directly impacted by impulsive noise and that 3,-30,000 workers
are indirectly impacted. The peak sound pressure levels ranged
from 35 to 147 cE with most of the levels greater than 115 dE.
However, r.c measure of the number of impulses per day per
worker were developed. In addition tc these workers, both
civilian and military personnel are likely to be exposed to
impulse noise, particularly gunfire and the manufacturing type
of operations used to refurbish military vehicles, ships, and
aircraft.
Other
r
K- 393 -
X-21
-------
TABLE K 13. EST IMATED OCCUPATIONAL NOISE EXPOSURE OF DEPARTMENT OF DEFENSE PERSONNEL.
Service
Total
Mi 1i tary
Population*
(thousands)
Military
at Levels
^85 dB
(thousands)
Total
Civilian
Population*
(thousands)
Civilian
at Levels
>85 dB
(thousands)
Total
Personnel*
(thousands)
Total
at Levels
>85 dB
(thousands)
Army
757
400.0
350
100.0
1107
500.0
Air Force
567
106.5
240
27.7
807
134.2
Navy
717
2 74.6
311
67.2
1028
341.8
Other
77
0.0
Total
2041
781.1
901
194.9
3019
976
*See Ref. K.39.
-------
The figures from these two studies suggest that a minimum of
1.2 to 4.6 million workers are exposed to impulsive noise.
K.8 Summary of Worker Noise Exposure Estimates
Table K.14 summarizes the exposure estimates developed in the
preceding sections.
TABLE K.14 SUMMARY OF U.S. POPULATION EXPOSED TO L (8 hr)
LEVELS OF 85 dB OR HIGHER FROM OCCUPATIONAL SOURCES
Employment
Area
Total
Employment
(thousands)
Total Number of People
Exposed to Greater Than
an L (8 hr) of 85 dB
(thousands)
Agriculture
3,600 tX.13~l
323
Mining
957 tX.29~.
400
Construction
4,644 [X.19"
513
Manufacturing and
Utility Industrial
21,781 [X.IS]
5,124
Transportation
4,345 IZ.IS]
1,934
Military (DOD)
3.019
976
Total of These Areas
38,346
-
3,270 j
On the basis of the figures in Table X.14 it is estimated tha
at least 2^% of the total number of employees in the
industrial, agricultural, transportation and military, sectors
are exposed tc levels greater than an Len (8 hr) of 35 dB.
-------
REFERENCES FOR APPENDIX K
K.l "Information on Levels of Environmental Noise Requisite
to Protect Public Health and Welfare with an Adequate
Margin of Safety," U.S. EPA 550/9-74-004, March 1974-
K.2 OSKA Safety and Health Standards, 29 CFR 1910-95.
K.3 OSHA Safety and Health Standards, 29 CFR 1926.52.
K.4 MSKA Safety Standards , 30 CFR 1.1, Subchapter M, Part 55,
Sections 55.5, 56.5, and 57.5; and Subchapter 0, part 70,
Subpart F, and Part 71, Subpart D.
X-5 Department of Defense Instruction, Hearing Conservation,
DOD Mo. 6055*3, S June 1976.
X.6 "The Effects of Tractor Noise on the Auditory Sensitivity
of Tractor Operations," Trans. An. Otol. Sec., 46, 1958.
X.7 Jones, H.H. and J.L. Oser, "Farm Equipment Noise Exposure
Levels," Am. Ind. Hyg. Assoc. J., 29, March-April, *1968,
p. 146-151.
K.8 "Nebraska Tractor Test Data 1977", University of
Nebraska-Lincoln, Department of Agricultural Engineering,
February 1977.
K.9 "Nebraska Tractor Test Data 1980", University of
Nebraska-Lincoln, Department of Agricultural Engineering,
January 1980.
K.10 Harris, J.D. , B.J. Lir.dgren, and R.L. Mann, "Assessment of
Occupational Noise Exposure and Associated Hearing Damage
Risk for Agricultural Employees," Paper 760673 presented
at the Off-Highway Vehicle Meeting of the Society of Auto-
motive Engineers in Milwaukee, VI, 13-16 September 1976.
X.ii Southwest Research Institute, "A Study of
Hearing Damage Risk for Operators of ?arm
Equipment", U.S. Department of Commerce/N?
oise
Ind
i« n a ^
r.d C 0
ns t
ruction
icr.al
—.' 1
reau of
1969.
/-s O *-
h 0
Ag r i —
K.12 Schnieder, R.D. and Sullivan, N., "A Report
cultural Operator Noise Exposure Research Program ir.
Nebraska", University of Nebraska, NI0SH Research Report,
1977.
-------
REFERENCES FOR APPENDIX K (CONTINUED)
K.13 "Farm Population of the United States: 1978", U.S. Depart-
ment of Commerce, U.S. Department of Agriculture, Series
Census - ERS, p. 27, No. 52, Issued September 1979-
K.14 Mining Enforcement and Safety Administration, "The Noise
Environment of the Underground Coal Mine", Information
Report Mo. 103^, 1976.
K.15 "1980 Keystone Coal Industry Manual", McGraw-Hill Eook
Co. Inc., 1980.
K.16 U.S. Department' of Health, Education and Welfare, National
Institute for Occupational Safety and Health, "Survey of
Hearing Loss in the Coal Mining Industry," Cincinnati, OH,
June 1976.
K.17 Bolt Beranek and Newman Inc., "The Noise Exposure of
Operators of Mobile Machines Used in U.S. Surface Coal
Mines", prepared for United States Department of the In-
terior, Bureau of Mines, Phase II Resort, Contract No.
J0166057, November 1977.
K.18 Bolt 3erar.ek and Newman Inc., "Noise of Diesel Powered
Underground Mining Equpment", prepared for the U.S. De-
oartment of the Interior, Bureau of Mines, 3BN Report No.
2979, Contract Nc. K03^6046, March 1975-
X.19 "Employment and Earnings, U.S. Department of Labor, Bureau
of Labor Statistics, Vol. 27, No. 3, March 1980
K.20 U.S. Bureau of the Census, "Statistical Abstract of the
United States 1975," 96th Edition, Washington, DC, 1975.
X.21 British Compressed Air Society PNEURO? Sound Test Code,
"Background and Experience of its Application", Report
Pu8/wg/10 and Appendix, Leicester House, London, England,
May 1971.
X.22 Gill, H.S., "Assessment, ' Prediction, ar.d Control of Noise
Exposure of Construction Plant Operators," Institute of
Sound and Vibration Research, I.3.V.R. Technical Report
Nc. 104, February 1980.
X.23 U.S. Bureau of the Census, Census of Population: 1970
Occupation by Industry, Final Report PC(2)-7C, U.S.
Government Printing Office, V.'ashington, DC, October 1S~2.
K-25
-------
REFERENCES POR APPENDIX K (CONTINUED)
K.24 U.S. 3ureau of the Census, 1970 Census of Population,
Classified Index of Industries and Occupations, U.S.
Goverment Printing Office, Washington, DC, 1971.
K.25 Federal Register, 46, No. 11, Friday, 16 January 1981,
Rules and Regulations, p.4109-
X.26 Bruce, R.D. et al., "Economic Impact Analysis of Proposed
Noise Control Regulations", B3N Report No. 3246, June
1976, Sponsored by U.S. D.0.L./0SHA.
K.27 U.S. Environmental Protection Agency, "Passenger Noise
Environments of Enclosed Transportation Systems", EPA
Report No. 550/9-75-025, June 1975.
X.28 Close, W.H. and Clarke, H.M., "Truck Noise--II: Interior
and Exterior A-Weighted Sound Levels of Typical Highway
Trucks," DOT Report No. OST/TST-72-2, 1972.
K.29 Merbornne, M.A. and Accardi, A.E., "Noise-Induced Hearing
Loss in a Truck Driver Population," J. of Aud. Res. 15:
119-122, 1975.
K.31" Federal Register, 33, No. 215, Thursday, 8 November 1973.
K.31 U.S. Environmental Protection Agency, Office of Noise
Abatement and Control - Noise Emissions Standards for
Transportation Eauioment - "Proposed Bus Noise Emission
Regulation", EPA *55*0/9-77-201, August 1977.
K.32 Kilmer, R.D., "Assessment of Locomotive Crew Ir.-Cab
Occupational Noi3e Exposure,1' U.S. DCT, FRA Report No.
FRA/ORD-8C/91, Washington DC, 1980.
K.32 Remington, F.J. and Rudd, M., "Assessment of Railroad
Locomotive Noise", 3BN Report No. 3189 for D07/TSC,
November 19 7 5•
K.34 Bender, E., et al, "Contribution to Background Document
for Rail Carrier Noise Regulations'', BBN Report submitted
to EPA, 5 December 1973.
K.35 Hanson, C.E., "Noise Measurements During Electric Loco-
motive Service Evaluation Tests: General Electric C-oC CP
and ASEA RC4", BBN Report No. 3524, submitted to Federal
Railroad Administration, Office of Passenger Systems,
July 1977,
K-26
-------
REFERENCES FOR APPENDIX K (CONTINUED)
K.36 Richiey, E.J. and Quinn, R.W., "MBTA Rapid Transit Sys-
tem (Red Line) Wayside and In-car Noise and Vibration
Levels", Final Report DOT-TSC-OST-72-31, August 1972.
K.37 Gerson, R.E., et al, "Rapid Transit Railroad Noise",
New York City Department of Air Resources, Bureau of
Noise Abatement, October X973•
K.38 Air Transport Association of America, "Air Transport
1979", 1980.
K.39 U.S. Department of Commerce, Bureau of the Census, " Sta-
tistical Abstract of the United States: 1979", 100th
Edition, Washington DC, September 1979-
X.40 Personal Communication, J. Goldstein, EPA/ONAC, 30 June
1980.
X.41 Personal Communication, Mr. Ed McCulloch, Vice President
and National Representative of Brotherhood of Locomotive
Engineers, Washington, DC, May 1981, developed from
Ref. K.U3.
K.42 "Yearbook of Railroad Facts, 1980 Edition, "Economics
and Finance Department, Association of American Railroads,
'Washington, DC, June 1930.
K.^3 American Public Transit Association, "Transit Operating
Report; for Calendar/Fiscal Year 1976," November 1978.
K.44 Federal Aviation Authority, Part 121.^71 Certification and
Operations, Domestic, Flag, and Supplemental Air Carrier
and Commercial Operators of Large Aircraft, Subpart Q,
Flight time limitations for domestic air carriers,
Washington, DC. (The limit is 100C hr per year.)
X.45 "Preliminary Summary of Noise Exposures," BEN Report 3 95^
for U.S. EPA, Task Order 16, EPA Contract No. 68-01-4i-8.
K. 6 Telephone conversation with Ms. Pat Beards lay of the FA A
Information and Statistics Office, Washington, DC,
19 September 1980.
K.47 Personal communication with Colonel Victor Furtado, Air
Force Medical Service Center, SGPA, Brooks Air Force Base,
San Antonio, TX, May 1981.
K-27
-------
REFERENCES FOR APPENDIX K (CONTINUED)
K.48 Personal communication with Dr. Douglas Ohlin,
Audiologist, Bio-Acoustics Division, "J.S. Army
Environmental Hygiene Agency, Aberdeen Proving Grounds,
MD, September 1980 and May 1981.
K.^9 Personal communication with Mr. James Green, U.S. Navy
Environmental Health Center, Virginia Beach, VA, Septem
ber 1980 and May 1981.
K.50 Poulos, A.C., Wasserman, D.E., and Doyle, T.E., "Occupa
tional Impact/Impulse Noise--An Overview," Sound and
Vibration, 14, No. 1, January 1980.
K.51 Dym, C.L., et al, "Identification of Occupational Impac
Impulsive Noise Sources", 3BN Report Mo. 3271, Prepared
for NIOSK under Contract No. 210-75-0068, April 19*76.
-------
APPENDIX L. TRANSPORTATION NOISE EXPOSURE OP OPERATORS AND
PASSENGERS
L.l Noise Exposure Model
The analysis of the noise impact on operators and passengers
of transportation vehicles In nonoccupational situations Is
based on
Average noise levels at the operator/passenger
positions during an ln-use duty cycle
Number of people exposed in the United States
Average duration of their annual exposure.
The annual Leq (24) for each type of equipment is derived
from the average sound level at the operator/passenger's posi-
tion on the basis of the estimated average annual exposure in
hours for that type of equipment.
The following transportation noise sources are assessed:
Aircraft
Automobiles
Trucks
Buses
Motorcycles
Rail Locomotives and Cars
Rapid Transit Cars.
L-l
-------
L.2 Noise Emission Levels
Noise source levels at the position of operators and passen-
gers have been taken from a number of sources, including the
EPA report on "Passenger Noise Environments of Enclosed
Transportation Systems" [L—1].
Noise in transportation vehicles characteristically rises and
falls in accordance with the duty cycle of the task at hand.
Passengers on city buses are exposed to intermittent noise as
the buses make frequent stops to receive or discharge passen-
gers, whereas much of the passenger's trip on intercity buses
is spent in the steady-cruise mode, with corresponding steady
noise levels. In addition, the trip lengths are different
between the two modes. For this study, the average sound
level over a characteristic trip was used, especially where
i:itermittency is the chief characteristic of the mode. Only
v.'here the trip consists of relatively long periods in cruise
conditions are the maximum power sound levels used to
represent the source level.
L.3 Population Distribution
The population exposed to noise in transportation vehicles was
estimated from a number of sources, including transit rider-
snip statistics, auto registrations, and aircraft enplanement
figures. The greatest uncertainty is use factors for private-
ly owned and operated vehicles, for which data on observed
driver behavior and personal experience of members of the
population being characterized were used.
-------
L.lJ Noise Exposure Estimates
Table L.l presents estimated noise levels at passenger and/or
operator locations, annual hours of exposure, and exposed-
population data for operators and passengers of transportation
noise sources In nonoccupational situations, based on these
average estimates. The 24-hour average annual exposure levels
[L»q(24)] shown in the table are computed from the
equation:
Leq(24) » LA + 10 log (H/8760), dB, (L.l)
where L^ Is the A-weighted sound exposure level, H is the
annual number of hours of exposure, and 8760 are number of
hours In a year.
As an example, for commercial Jets:
Lgq(24) -85+10 log (5/8760) - 85 - 32.4
= 53 dB. (L.2)
These estimates for the Impact of transportation system noise
on passengers must be viewed with care. To produce an esti-
mate, it was necessary to use average sound levels and average
annual exposures. Especially difficult to estimate, for al-
most all sources, is the number of "repeat riders." For exam-
ple, though statistics are often available on "passenger
miles" or "total trips" per year, for many modes cf transpor-
tation almost no data are available that show how many times
per year an average passenger uses a particular node of trans-
portation. Thus, though the data readily yield the total
person-hours of exposure per year, the data do not show how
many people share this total exposure.
-------
TABLE 1.1. TRANSPORTATION HOISE EXPOSURE DATA AND IMPACT
ESTIMATES (NONOCCUPATIONAL).
A-wei ghted
Annual
Population
Sound Level
Exposure
'-eq (24)
Exposed
Source
(dB)
(hr)
(dB)
(x 10s)
A
ire raft
Commercial Jet
35
5
53
81.3
L-l, L—3j L—41L-22 j
General Aviation
91*
100
75
0.37
[L-l,L-2,L-23]
Helicopters
9k
20
68
0.06
[L-l,L-22]
Automobiles
75
313
61
1:? .0
\L-1 ,L-5 ,LS} L-7 ,L-13 j
i
Motorcycles
q3
15C
•30
I
. 2 :
[On road!
.8j u~i 3, ti~l9 ,
Trucks
85
180
68
5.7
Personal Use)
i
[L-5}L-9}L-JS]
Buses
Intercity
30
9
50
66
^L—1,L—4,L—10}L—1£ j
!
Consult er
5U
500
72 '
10. *
.Ij—lyL —1 0 y Li —11 y Li —1 t y
L-22]
r.ai I road
Ccasnuter Cars
T3
155
56
.0.5
* r —i r-fO t 1 £ 1
k 1/ -i ) ^ ^ iO !
Rapid Transit
Heavy Hail)
[L-ll >L-12 ,L-13 ,L -15
L-2 0'
NY City [L-Z4yL-2S,L-17)
93
225
'
2. C
3ther ! L-2yL-lS,L~1S j
65
229
69
- *»
i—
Ir-4
-------
REFERENCES FOR APPENDIX L
L-l U.S. Environmental Protection Agency, "Passenger Noise
Environments of Enclosed Transportation Systems," EPA
Report No. 550/9-75-025, June 1975.
L-2 Administrator of the EPA, "Report to the President and
Congress on Noise," In compliance with Title IV of Public
Law 01-60^, The Clean Air Act Amendments of 1970, Senate
Document 92—63, U.S. Government Printing Office, February
1972.
L-3 Department of Transportation, Federal Aviation
Administration, "FAA Statistical Handbook of Aviation:
1975 edition," U.S. Government Printing Office, 1975-
L-4 U.S. Department of Transportation, "Summary of National
Transportation Statistics," Report No. DOT-TSC-OST-77-6B,
U.S. Government Printing Office, November 1977.
L-5 U.S. Department of Commerce, Bureau of the Census,
Statistical Abstract af the United States: 1977, 98th
Edition, September 1?77.
L-6 B.J. Challen and D.Morrison, "Passenger Car Noise -
Diesel and Gasoline,' Proc. of INTER-NOISE 78, May 1976,
p. 883.
L-7 R.C. Potter et al., "Effectiveness of Audible Warning
Devices on Emergency Vehicles," U.S. Department of Trans-
portation, DOT-TSC-OST-77-38, August 1977.
L-8 U.S. Environmental Protection Agency, Office of Noise
Abatement and Control, "Proposed Motorcycle Noise Emis-
sion Regulations," Background Document, EPA 550/9-77-203,
November 1977.
L-9 J.E. Webster, "Highway Traffic Noise Prediction: A
State-of-the-Art Review," Sound and Vibration, February
1977.
L-10 U.S. Environmental Protection Agency, Office of Noise
Abatement and Control - Noise Emission Standards for
Transportation Equipment, "Proposed Bus Noise Emission
Regulation," SPA 550/9-77-201, August 1972.
-------
REFERENCES FOR APPENDIX L (CONTINUED)
L-ll American Public Transit Association, Transit Fact Book,
1976-1977 Edition, ISSN 0092-5913, June 1977.
L-12 American Institute of Planners, Motor Vehicle Manufactur-
ers Association of the U.S. Inc., "Urban Transportation
Fact Book," March 1974.
L-13 E.J. Richley and R.W. Quinn, "Massachusetts 3ay Trans-
portation Authority, Rapid Transit System (Red Line)
Wayside and In-Car Noise and Vibration Levels," Depart-
ment of Transportation Report No. DOT-TSC-OST-72-31,
August 1972.
L-H» R.E. Gerson et al, "Rapid Transit Railroad Noise," New
York City Department of Air Resources, Bureau of Noise
Abatement, October,1973•
L-15 L. Kurzweil, "Rapid Transit Noise Abatement - Present
State of the Art," U.S. Department of Transportation,
Prepared statement presented to the NYS Assembly Sub-
committee on Public Authorities in Relation to the
Hearings on the NYCTA Noise Abatement Program, August
11, 1977.
L-16 American Public Transit Association, Transit Fact Book,
1978-1979 Edition, ISSN 0149-3132, December 1979-
L-17 P.J.. Remington, "Reduction of Noise Generated by Rapid
Transit Cars," 3BN Report No. 4086, July 1979-
L-18 U.S. Department of Commerce, Bureau of the Census, Sta-
tistical Abstract of the United States: 1979. 100th
Edition, September 197S•
L—19 Motor Vehicle Manufacturers Association, "MVMA Motor
Vehicle Facts and Figures '79."
L-20 G. Chisholm et al., "National Assessment of Urban Rail
Noise," U.S. Department of Transportation Resort No.
UMTA-MA-06-0099-79-2, March 1979".
L-21 U.S. Environmental Protection Agency, "Proposed Eus Noise
Emission Regulation," EPA 550/9-77-2C1, August 1977.
L.-6
-------
REFERENCES FOR APPENDIX L (CONTINUED)
L-22 Department of Transportation, Federal Aviation Adminis-
tration, "FAA Statistical Handbook of Aviation, Calendar
Year 1977," December 1977.
L-23 Aircraft Owners and Pilots Association, "Fact Card,"
1978.
L-7
-------
APPENDIX M. RECREATIONAL NOISE EXPOSURE OP OPERATORS AND
PASSENGERS
M.l Noise Exposure Model
The noise exposure of operators and passengers on recreational
vehicles is modeled in a manner identical to that described
for transportation vehicles (see Appendix L). The followin|
recreational noise sources are assessed:
Snowmobiles
. -Motorcycles
Pleasure boats
Racing cars.
M.2 Noise Emission Levels
Noise source levels of recreational vehicles have been taken
from data in the open literature. In many cases, data were
available on nci3e levels at the operator's ear. Auto racing
cars were an exception, and the estimates are based on pro-
jecting the 50-ft sound level back to the interior of the
car.
As in the case of transportation vehicles, the tine history cf
noise exposure is intermittent; it is based or. the desired use
of the equipment. A distinction can be made, however; the
operator of a recreational vehicle has freedom in selection of
the duty cycle, whereas the operator/passenger of a transpor-
tation vehicle is restricted to a pattern of actions based on
the trip definition. As a result, there is a greater inac-
curacy in estimating the average noise level during exposure
of an operator of a recreational vehicle.
-------
M.3 Noise Exposure Estimates
Table M.l presents the sound level, annual exposure, and
exposed-population data for each of the recreational noise
sources. The equivalent 2^-bour exposure [Lea(24)] is
computed from the equation
Leq(2*0 - LA + 10 log (H/8760) , dB, (M.l)
where is the A-weighted sound exposure level, H is the
annual number of exposure hours, and 8760 is the number of
hours in a year.
As an example, for snowmobiles
Lsq(2iJ) = 102 + 10 log (80/8760) = 102 - 20.4
= 8 2 dB, (M . 2 )
-------
TABLE H.l. RECREATIONAL NOISE EXPOSURE DATA AND IMPACT
ESTIMATES.
Source
A-weighted
Sound Level
(dB)
Annual
Exposure
(hr)
Lth\U)
Population
Exposed
(x 10s)
.SNOWMOBILES [M-l,M-2t
M-10]
102
80
82
1.7
MOTORCYCLES [M-3,M-4,
M-9 ]
(off-road)
1C0
eo
8Q
2.6
MCTCRBOATS [MS,MS,
M-?SM-11 • *
< 10 hp
83
100
69
11.2
10-50 hp
85
100
66
12.9
Q*
&
O
ITS
A
S3
100
¦ 69
3.9
Inboard/outboard
91
100
12
2.3
Inboard
8U
100
65
li.7
AUTO RACING [MS]
Oval Track Racing
105
10li
86
0 .Oli
Drag Racing
Not Supercharged
122
l
83
o.c8
Drag Racing
Supercharged
ll+O
0.<4
97
0.01
Sports Car Racing
105
138
57
c+
Tractor Pulls
115
12
92
0.01
* Mctorboat source levels based on 50% of time at full throttle, 50% of
time at half throttle.
x Less thai: 5000.
-------
REFERENCES FOR APPENDIX M
M-l R. Harrison, "Snowmobile Noise/1 Equipment Development
and Test Report No. 7120-5, U.S. Department of Agricul-
ture, Forest Service, January 1974.
M-2 D. Crandall, "Three State Snowmobile Economic and Prefer-
ence Survey," International Snowmobile Industry Associa-
tion Study by Upper Great Lakes Regional Commission,
1974.
M-3 R. Harrison, "Motorcycle Noise," U.S. Department of Agri-
culture, Forest Service, February 1974.
M-4 U.S. Environmental Protection Agency, Office of Noise
Abatement and Control - Noise Emission Standards for
Transportation Vehicles - Proposed Motorcycle Noise
Emissions Regulations," EPA 550/9-77-203, November 1977-
M-5 S.R. Skale, "Cost Effectiveness Study of Major Sources
of Noise," Volume VI: Motorboats, Wyie Research Report
WR 73-1. March 1574.
M-6 "The Boiting Business: 1975," Boating; Industry, A
Conover -Mast publication.
M-7 S.R. Ma^rab, "The Establishment of Noise Criteria for
Recreational Eoats," prepared for the U.S. Coast Guard,
July 1973.
M-8 R.C. Potter, "The Acoustic Impact of Motor Racing in the
State of Illinois," B3N Report No. 3214, prepared for the
Association of Motor Sports, January 1976.
M-9 U.S. Department of Commerce, Bureau of the Census, Sta-
tistical Abstract of the United States: 1979, 100th
Edition,. September 1979-
M-10 Personal communication, International Snowmobile Insti-
tute, Washington, DC.
M-ll MA REX, "Boating '79,'' 401 U. Michigan Avenue, Chicago IL
60611.
M-4
-------
TECHNICAL REPORT DATA
(Please read /nsrrucnons on the reverse before completing;
1.REPORTNO. 2. |3. RECIPIENT'S ACCESSION NO.
550/9-01 -101 ! PB8^ 21918 9
A, TITLE ANO subtitle
Noise in America: Extent of the Noise Problem
S. REPORT OATS
Sentember 1981
6. performing ORGANIZATION CODE
7. AUTHOR(S)
Prepared by Miles Simpson and Robert Bruce
a. PERFORMING ORGANIZATION REPORT NO.
550/9-81-101
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
Bolt 3eranek and Newman, Inc.
21120 Vanowen Street
Los Angeles, CA 91303
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME ANO ADDRESS
Environmental Protection Aqencv (EPA)
Office of Noise Abatement and Control (0NAC)
Wasnington, D.C. 20460
13. TYPE OF REPORT ANO PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA CUftC
18. SUPPLEMENTARY NOTES
16. ABSTRACT
i
The number of Americans exposed to various levels of occupational and environmental
noise is estimated. Estimates are made for ll categories of noise producers (e.g.,
traffic, aircraft, construction) using the Ldn or-Leq(24) metrics. The assumptions
in the models used, including demographic projections, are made explicit for all
estimates. Estimates for combined exDo'sures to traffic and other community noise
sources are also made, as well as indoor noise exposures from home equipment like
fans and clothes washers. According.to the estimates, I.5 million people are
exposed to outdoor noise levels (from all sources)- of over 75 Ldn, and over 90
million, to levels over 58 Ldn. Over 9 million people are exposed to occupational
noise in excess of 80 dB (Leq(.24)).
17. KEY WORDS ANO DOCUMENT ANALYSIS
a. DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED *ERMS
c. cosati Field/Group
Traffic Noise, Ambient Noise Occupational
Noise, Home Applicance Noise Aircraft Nois<
Construction Noise, Agricultural Noise.
Mechanical Equipment Noise, Noise ExDosure
Community Noise Exposure, Recreational
Noise. Environmental Noise, Noise Control
Noise Pollution
J
18. DISTRIBUTION STATEMENT
Available Throuah EPA/0MAC or National
Technical Information Service (NTIS)
I
19. SECURITY CLASS (Thu Report)
UNCLASSIFIED
31. NO. OF PAGES
184
20. SECURITY CLASS
------- |